add code for analysis of data

20 files changed, 4069 insertions, 0 deletions

diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/__init__.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/__init__.py
new file mode 100644
index 0000000..846ffce
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/__init__.py
@@ -0,0 +1,34 @@
+from .accept import Accept as Accept
+from .accept import CharsetAccept as CharsetAccept
+from .accept import LanguageAccept as LanguageAccept
+from .accept import MIMEAccept as MIMEAccept
+from .auth import Authorization as Authorization
+from .auth import WWWAuthenticate as WWWAuthenticate
+from .cache_control import RequestCacheControl as RequestCacheControl
+from .cache_control import ResponseCacheControl as ResponseCacheControl
+from .csp import ContentSecurityPolicy as ContentSecurityPolicy
+from .etag import ETags as ETags
+from .file_storage import FileMultiDict as FileMultiDict
+from .file_storage import FileStorage as FileStorage
+from .headers import EnvironHeaders as EnvironHeaders
+from .headers import Headers as Headers
+from .mixins import ImmutableDictMixin as ImmutableDictMixin
+from .mixins import ImmutableHeadersMixin as ImmutableHeadersMixin
+from .mixins import ImmutableListMixin as ImmutableListMixin
+from .mixins import ImmutableMultiDictMixin as ImmutableMultiDictMixin
+from .mixins import UpdateDictMixin as UpdateDictMixin
+from .range import ContentRange as ContentRange
+from .range import IfRange as IfRange
+from .range import Range as Range
+from .structures import CallbackDict as CallbackDict
+from .structures import CombinedMultiDict as CombinedMultiDict
+from .structures import HeaderSet as HeaderSet
+from .structures import ImmutableDict as ImmutableDict
+from .structures import ImmutableList as ImmutableList
+from .structures import ImmutableMultiDict as ImmutableMultiDict
+from .structures import ImmutableOrderedMultiDict as ImmutableOrderedMultiDict
+from .structures import ImmutableTypeConversionDict as ImmutableTypeConversionDict
+from .structures import iter_multi_items as iter_multi_items
+from .structures import MultiDict as MultiDict
+from .structures import OrderedMultiDict as OrderedMultiDict
+from .structures import TypeConversionDict as TypeConversionDict
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.py
new file mode 100644
index 0000000..d80f0bb
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.py
@@ -0,0 +1,326 @@
+from __future__ import annotations
+
+import codecs
+import re
+
+from .structures import ImmutableList
+
+
+class Accept(ImmutableList):
+    """An :class:`Accept` object is just a list subclass for lists of
+    ``(value, quality)`` tuples.  It is automatically sorted by specificity
+    and quality.
+
+    All :class:`Accept` objects work similar to a list but provide extra
+    functionality for working with the data.  Containment checks are
+    normalized to the rules of that header:
+
+    >>> a = CharsetAccept([('ISO-8859-1', 1), ('utf-8', 0.7)])
+    >>> a.best
+    'ISO-8859-1'
+    >>> 'iso-8859-1' in a
+    True
+    >>> 'UTF8' in a
+    True
+    >>> 'utf7' in a
+    False
+
+    To get the quality for an item you can use normal item lookup:
+
+    >>> print a['utf-8']
+    0.7
+    >>> a['utf7']
+    0
+
+    .. versionchanged:: 0.5
+       :class:`Accept` objects are forced immutable now.
+
+    .. versionchanged:: 1.0.0
+       :class:`Accept` internal values are no longer ordered
+       alphabetically for equal quality tags. Instead the initial
+       order is preserved.
+
+    """
+
+    def __init__(self, values=()):
+        if values is None:
+            list.__init__(self)
+            self.provided = False
+        elif isinstance(values, Accept):
+            self.provided = values.provided
+            list.__init__(self, values)
+        else:
+            self.provided = True
+            values = sorted(
+                values, key=lambda x: (self._specificity(x[0]), x[1]), reverse=True
+            )
+            list.__init__(self, values)
+
+    def _specificity(self, value):
+        """Returns a tuple describing the value's specificity."""
+        return (value != "*",)
+
+    def _value_matches(self, value, item):
+        """Check if a value matches a given accept item."""
+        return item == "*" or item.lower() == value.lower()
+
+    def __getitem__(self, key):
+        """Besides index lookup (getting item n) you can also pass it a string
+        to get the quality for the item.  If the item is not in the list, the
+        returned quality is ``0``.
+        """
+        if isinstance(key, str):
+            return self.quality(key)
+        return list.__getitem__(self, key)
+
+    def quality(self, key):
+        """Returns the quality of the key.
+
+        .. versionadded:: 0.6
+           In previous versions you had to use the item-lookup syntax
+           (eg: ``obj[key]`` instead of ``obj.quality(key)``)
+        """
+        for item, quality in self:
+            if self._value_matches(key, item):
+                return quality
+        return 0
+
+    def __contains__(self, value):
+        for item, _quality in self:
+            if self._value_matches(value, item):
+                return True
+        return False
+
+    def __repr__(self):
+        pairs_str = ", ".join(f"({x!r}, {y})" for x, y in self)
+        return f"{type(self).__name__}([{pairs_str}])"
+
+    def index(self, key):
+        """Get the position of an entry or raise :exc:`ValueError`.
+
+        :param key: The key to be looked up.
+
+        .. versionchanged:: 0.5
+           This used to raise :exc:`IndexError`, which was inconsistent
+           with the list API.
+        """
+        if isinstance(key, str):
+            for idx, (item, _quality) in enumerate(self):
+                if self._value_matches(key, item):
+                    return idx
+            raise ValueError(key)
+        return list.index(self, key)
+
+    def find(self, key):
+        """Get the position of an entry or return -1.
+
+        :param key: The key to be looked up.
+        """
+        try:
+            return self.index(key)
+        except ValueError:
+            return -1
+
+    def values(self):
+        """Iterate over all values."""
+        for item in self:
+            yield item[0]
+
+    def to_header(self):
+        """Convert the header set into an HTTP header string."""
+        result = []
+        for value, quality in self:
+            if quality != 1:
+                value = f"{value};q={quality}"
+            result.append(value)
+        return ",".join(result)
+
+    def __str__(self):
+        return self.to_header()
+
+    def _best_single_match(self, match):
+        for client_item, quality in self:
+            if self._value_matches(match, client_item):
+                # self is sorted by specificity descending, we can exit
+                return client_item, quality
+        return None
+
+    def best_match(self, matches, default=None):
+        """Returns the best match from a list of possible matches based
+        on the specificity and quality of the client. If two items have the
+        same quality and specificity, the one is returned that comes first.
+
+        :param matches: a list of matches to check for
+        :param default: the value that is returned if none match
+        """
+        result = default
+        best_quality = -1
+        best_specificity = (-1,)
+        for server_item in matches:
+            match = self._best_single_match(server_item)
+            if not match:
+                continue
+            client_item, quality = match
+            specificity = self._specificity(client_item)
+            if quality <= 0 or quality < best_quality:
+                continue
+            # better quality or same quality but more specific => better match
+            if quality > best_quality or specificity > best_specificity:
+                result = server_item
+                best_quality = quality
+                best_specificity = specificity
+        return result
+
+    @property
+    def best(self):
+        """The best match as value."""
+        if self:
+            return self[0][0]
+
+
+_mime_split_re = re.compile(r"/|(?:\s*;\s*)")
+
+
+def _normalize_mime(value):
+    return _mime_split_re.split(value.lower())
+
+
+class MIMEAccept(Accept):
+    """Like :class:`Accept` but with special methods and behavior for
+    mimetypes.
+    """
+
+    def _specificity(self, value):
+        return tuple(x != "*" for x in _mime_split_re.split(value))
+
+    def _value_matches(self, value, item):
+        # item comes from the client, can't match if it's invalid.
+        if "/" not in item:
+            return False
+
+        # value comes from the application, tell the developer when it
+        # doesn't look valid.
+        if "/" not in value:
+            raise ValueError(f"invalid mimetype {value!r}")
+
+        # Split the match value into type, subtype, and a sorted list of parameters.
+        normalized_value = _normalize_mime(value)
+        value_type, value_subtype = normalized_value[:2]
+        value_params = sorted(normalized_value[2:])
+
+        # "*/*" is the only valid value that can start with "*".
+        if value_type == "*" and value_subtype != "*":
+            raise ValueError(f"invalid mimetype {value!r}")
+
+        # Split the accept item into type, subtype, and parameters.
+        normalized_item = _normalize_mime(item)
+        item_type, item_subtype = normalized_item[:2]
+        item_params = sorted(normalized_item[2:])
+
+        # "*/not-*" from the client is invalid, can't match.
+        if item_type == "*" and item_subtype != "*":
+            return False
+
+        return (
+            (item_type == "*" and item_subtype == "*")
+            or (value_type == "*" and value_subtype == "*")
+        ) or (
+            item_type == value_type
+            and (
+                item_subtype == "*"
+                or value_subtype == "*"
+                or (item_subtype == value_subtype and item_params == value_params)
+            )
+        )
+
+    @property
+    def accept_html(self):
+        """True if this object accepts HTML."""
+        return (
+            "text/html" in self or "application/xhtml+xml" in self or self.accept_xhtml
+        )
+
+    @property
+    def accept_xhtml(self):
+        """True if this object accepts XHTML."""
+        return "application/xhtml+xml" in self or "application/xml" in self
+
+    @property
+    def accept_json(self):
+        """True if this object accepts JSON."""
+        return "application/json" in self
+
+
+_locale_delim_re = re.compile(r"[_-]")
+
+
+def _normalize_lang(value):
+    """Process a language tag for matching."""
+    return _locale_delim_re.split(value.lower())
+
+
+class LanguageAccept(Accept):
+    """Like :class:`Accept` but with normalization for language tags."""
+
+    def _value_matches(self, value, item):
+        return item == "*" or _normalize_lang(value) == _normalize_lang(item)
+
+    def best_match(self, matches, default=None):
+        """Given a list of supported values, finds the best match from
+        the list of accepted values.
+
+        Language tags are normalized for the purpose of matching, but
+        are returned unchanged.
+
+        If no exact match is found, this will fall back to matching
+        the first subtag (primary language only), first with the
+        accepted values then with the match values. This partial is not
+        applied to any other language subtags.
+
+        The default is returned if no exact or fallback match is found.
+
+        :param matches: A list of supported languages to find a match.
+        :param default: The value that is returned if none match.
+        """
+        # Look for an exact match first. If a client accepts "en-US",
+        # "en-US" is a valid match at this point.
+        result = super().best_match(matches)
+
+        if result is not None:
+            return result
+
+        # Fall back to accepting primary tags. If a client accepts
+        # "en-US", "en" is a valid match at this point. Need to use
+        # re.split to account for 2 or 3 letter codes.
+        fallback = Accept(
+            [(_locale_delim_re.split(item[0], 1)[0], item[1]) for item in self]
+        )
+        result = fallback.best_match(matches)
+
+        if result is not None:
+            return result
+
+        # Fall back to matching primary tags. If the client accepts
+        # "en", "en-US" is a valid match at this point.
+        fallback_matches = [_locale_delim_re.split(item, 1)[0] for item in matches]
+        result = super().best_match(fallback_matches)
+
+        # Return a value from the original match list. Find the first
+        # original value that starts with the matched primary tag.
+        if result is not None:
+            return next(item for item in matches if item.startswith(result))
+
+        return default
+
+
+class CharsetAccept(Accept):
+    """Like :class:`Accept` but with normalization for charsets."""
+
+    def _value_matches(self, value, item):
+        def _normalize(name):
+            try:
+                return codecs.lookup(name).name
+            except LookupError:
+                return name.lower()
+
+        return item == "*" or _normalize(value) == _normalize(item)
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.pyi
new file mode 100644
index 0000000..4b74dd9
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/accept.pyi
@@ -0,0 +1,54 @@
+from collections.abc import Iterable
+from collections.abc import Iterator
+from typing import overload
+
+from .structures import ImmutableList
+
+class Accept(ImmutableList[tuple[str, int]]):
+    provided: bool
+    def __init__(
+        self, values: Accept | Iterable[tuple[str, float]] | None = None
+    ) -> None: ...
+    def _specificity(self, value: str) -> tuple[bool, ...]: ...
+    def _value_matches(self, value: str, item: str) -> bool: ...
+    @overload  # type: ignore
+    def __getitem__(self, key: str) -> int: ...
+    @overload
+    def __getitem__(self, key: int) -> tuple[str, int]: ...
+    @overload
+    def __getitem__(self, key: slice) -> Iterable[tuple[str, int]]: ...
+    def quality(self, key: str) -> int: ...
+    def __contains__(self, value: str) -> bool: ...  # type: ignore
+    def index(self, key: str) -> int: ...  # type: ignore
+    def find(self, key: str) -> int: ...
+    def values(self) -> Iterator[str]: ...
+    def to_header(self) -> str: ...
+    def _best_single_match(self, match: str) -> tuple[str, int] | None: ...
+    @overload
+    def best_match(self, matches: Iterable[str], default: str) -> str: ...
+    @overload
+    def best_match(
+        self, matches: Iterable[str], default: str | None = None
+    ) -> str | None: ...
+    @property
+    def best(self) -> str: ...
+
+def _normalize_mime(value: str) -> list[str]: ...
+
+class MIMEAccept(Accept):
+    def _specificity(self, value: str) -> tuple[bool, ...]: ...
+    def _value_matches(self, value: str, item: str) -> bool: ...
+    @property
+    def accept_html(self) -> bool: ...
+    @property
+    def accept_xhtml(self) -> bool: ...
+    @property
+    def accept_json(self) -> bool: ...
+
+def _normalize_lang(value: str) -> list[str]: ...
+
+class LanguageAccept(Accept):
+    def _value_matches(self, value: str, item: str) -> bool: ...
+
+class CharsetAccept(Accept):
+    def _value_matches(self, value: str, item: str) -> bool: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/auth.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/auth.py
new file mode 100644
index 0000000..a3ca0de
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/auth.py
@@ -0,0 +1,316 @@
+from __future__ import annotations
+
+import base64
+import binascii
+import typing as t
+
+from ..http import dump_header
+from ..http import parse_dict_header
+from ..http import quote_header_value
+from .structures import CallbackDict
+
+if t.TYPE_CHECKING:
+    import typing_extensions as te
+
+
+class Authorization:
+    """Represents the parts of an ``Authorization`` request header.
+
+    :attr:`.Request.authorization` returns an instance if the header is set.
+
+    An instance can be used with the test :class:`.Client` request methods' ``auth``
+    parameter to send the header in test requests.
+
+    Depending on the auth scheme, either :attr:`parameters` or :attr:`token` will be
+    set. The ``Basic`` scheme's token is decoded into the ``username`` and ``password``
+    parameters.
+
+    For convenience, ``auth["key"]`` and ``auth.key`` both access the key in the
+    :attr:`parameters` dict, along with ``auth.get("key")`` and ``"key" in auth``.
+
+    .. versionchanged:: 2.3
+        The ``token`` parameter and attribute was added to support auth schemes that use
+        a token instead of parameters, such as ``Bearer``.
+
+    .. versionchanged:: 2.3
+        The object is no longer a ``dict``.
+
+    .. versionchanged:: 0.5
+        The object is an immutable dict.
+    """
+
+    def __init__(
+        self,
+        auth_type: str,
+        data: dict[str, str | None] | None = None,
+        token: str | None = None,
+    ) -> None:
+        self.type = auth_type
+        """The authorization scheme, like ``basic``, ``digest``, or ``bearer``."""
+
+        if data is None:
+            data = {}
+
+        self.parameters = data
+        """A dict of parameters parsed from the header. Either this or :attr:`token`
+        will have a value for a given scheme.
+        """
+
+        self.token = token
+        """A token parsed from the header. Either this or :attr:`parameters` will have a
+        value for a given scheme.
+
+        .. versionadded:: 2.3
+        """
+
+    def __getattr__(self, name: str) -> str | None:
+        return self.parameters.get(name)
+
+    def __getitem__(self, name: str) -> str | None:
+        return self.parameters.get(name)
+
+    def get(self, key: str, default: str | None = None) -> str | None:
+        return self.parameters.get(key, default)
+
+    def __contains__(self, key: str) -> bool:
+        return key in self.parameters
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, Authorization):
+            return NotImplemented
+
+        return (
+            other.type == self.type
+            and other.token == self.token
+            and other.parameters == self.parameters
+        )
+
+    @classmethod
+    def from_header(cls, value: str | None) -> te.Self | None:
+        """Parse an ``Authorization`` header value and return an instance, or ``None``
+        if the value is empty.
+
+        :param value: The header value to parse.
+
+        .. versionadded:: 2.3
+        """
+        if not value:
+            return None
+
+        scheme, _, rest = value.partition(" ")
+        scheme = scheme.lower()
+        rest = rest.strip()
+
+        if scheme == "basic":
+            try:
+                username, _, password = base64.b64decode(rest).decode().partition(":")
+            except (binascii.Error, UnicodeError):
+                return None
+
+            return cls(scheme, {"username": username, "password": password})
+
+        if "=" in rest.rstrip("="):
+            # = that is not trailing, this is parameters.
+            return cls(scheme, parse_dict_header(rest), None)
+
+        # No = or only trailing =, this is a token.
+        return cls(scheme, None, rest)
+
+    def to_header(self) -> str:
+        """Produce an ``Authorization`` header value representing this data.
+
+        .. versionadded:: 2.0
+        """
+        if self.type == "basic":
+            value = base64.b64encode(
+                f"{self.username}:{self.password}".encode()
+            ).decode("ascii")
+            return f"Basic {value}"
+
+        if self.token is not None:
+            return f"{self.type.title()} {self.token}"
+
+        return f"{self.type.title()} {dump_header(self.parameters)}"
+
+    def __str__(self) -> str:
+        return self.to_header()
+
+    def __repr__(self) -> str:
+        return f"<{type(self).__name__} {self.to_header()}>"
+
+
+class WWWAuthenticate:
+    """Represents the parts of a ``WWW-Authenticate`` response header.
+
+    Set :attr:`.Response.www_authenticate` to an instance of list of instances to set
+    values for this header in the response. Modifying this instance will modify the
+    header value.
+
+    Depending on the auth scheme, either :attr:`parameters` or :attr:`token` should be
+    set. The ``Basic`` scheme will encode ``username`` and ``password`` parameters to a
+    token.
+
+    For convenience, ``auth["key"]`` and ``auth.key`` both act on the :attr:`parameters`
+    dict, and can be used to get, set, or delete parameters. ``auth.get("key")`` and
+    ``"key" in auth`` are also provided.
+
+    .. versionchanged:: 2.3
+        The ``token`` parameter and attribute was added to support auth schemes that use
+        a token instead of parameters, such as ``Bearer``.
+
+    .. versionchanged:: 2.3
+        The object is no longer a ``dict``.
+
+    .. versionchanged:: 2.3
+        The ``on_update`` parameter was removed.
+    """
+
+    def __init__(
+        self,
+        auth_type: str,
+        values: dict[str, str | None] | None = None,
+        token: str | None = None,
+    ):
+        self._type = auth_type.lower()
+        self._parameters: dict[str, str | None] = CallbackDict(
+            values, lambda _: self._trigger_on_update()
+        )
+        self._token = token
+        self._on_update: t.Callable[[WWWAuthenticate], None] | None = None
+
+    def _trigger_on_update(self) -> None:
+        if self._on_update is not None:
+            self._on_update(self)
+
+    @property
+    def type(self) -> str:
+        """The authorization scheme, like ``basic``, ``digest``, or ``bearer``."""
+        return self._type
+
+    @type.setter
+    def type(self, value: str) -> None:
+        self._type = value
+        self._trigger_on_update()
+
+    @property
+    def parameters(self) -> dict[str, str | None]:
+        """A dict of parameters for the header. Only one of this or :attr:`token` should
+        have a value for a given scheme.
+        """
+        return self._parameters
+
+    @parameters.setter
+    def parameters(self, value: dict[str, str]) -> None:
+        self._parameters = CallbackDict(value, lambda _: self._trigger_on_update())
+        self._trigger_on_update()
+
+    @property
+    def token(self) -> str | None:
+        """A dict of parameters for the header. Only one of this or :attr:`token` should
+        have a value for a given scheme.
+        """
+        return self._token
+
+    @token.setter
+    def token(self, value: str | None) -> None:
+        """A token for the header. Only one of this or :attr:`parameters` should have a
+        value for a given scheme.
+
+        .. versionadded:: 2.3
+        """
+        self._token = value
+        self._trigger_on_update()
+
+    def __getitem__(self, key: str) -> str | None:
+        return self.parameters.get(key)
+
+    def __setitem__(self, key: str, value: str | None) -> None:
+        if value is None:
+            if key in self.parameters:
+                del self.parameters[key]
+        else:
+            self.parameters[key] = value
+
+        self._trigger_on_update()
+
+    def __delitem__(self, key: str) -> None:
+        if key in self.parameters:
+            del self.parameters[key]
+            self._trigger_on_update()
+
+    def __getattr__(self, name: str) -> str | None:
+        return self[name]
+
+    def __setattr__(self, name: str, value: str | None) -> None:
+        if name in {"_type", "_parameters", "_token", "_on_update"}:
+            super().__setattr__(name, value)
+        else:
+            self[name] = value
+
+    def __delattr__(self, name: str) -> None:
+        del self[name]
+
+    def __contains__(self, key: str) -> bool:
+        return key in self.parameters
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, WWWAuthenticate):
+            return NotImplemented
+
+        return (
+            other.type == self.type
+            and other.token == self.token
+            and other.parameters == self.parameters
+        )
+
+    def get(self, key: str, default: str | None = None) -> str | None:
+        return self.parameters.get(key, default)
+
+    @classmethod
+    def from_header(cls, value: str | None) -> te.Self | None:
+        """Parse a ``WWW-Authenticate`` header value and return an instance, or ``None``
+        if the value is empty.
+
+        :param value: The header value to parse.
+
+        .. versionadded:: 2.3
+        """
+        if not value:
+            return None
+
+        scheme, _, rest = value.partition(" ")
+        scheme = scheme.lower()
+        rest = rest.strip()
+
+        if "=" in rest.rstrip("="):
+            # = that is not trailing, this is parameters.
+            return cls(scheme, parse_dict_header(rest), None)
+
+        # No = or only trailing =, this is a token.
+        return cls(scheme, None, rest)
+
+    def to_header(self) -> str:
+        """Produce a ``WWW-Authenticate`` header value representing this data."""
+        if self.token is not None:
+            return f"{self.type.title()} {self.token}"
+
+        if self.type == "digest":
+            items = []
+
+            for key, value in self.parameters.items():
+                if key in {"realm", "domain", "nonce", "opaque", "qop"}:
+                    value = quote_header_value(value, allow_token=False)
+                else:
+                    value = quote_header_value(value)
+
+                items.append(f"{key}={value}")
+
+            return f"Digest {', '.join(items)}"
+
+        return f"{self.type.title()} {dump_header(self.parameters)}"
+
+    def __str__(self) -> str:
+        return self.to_header()
+
+    def __repr__(self) -> str:
+        return f"<{type(self).__name__} {self.to_header()}>"
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.py
new file mode 100644
index 0000000..bff4c18
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.py
@@ -0,0 +1,175 @@
+from __future__ import annotations
+
+from .mixins import ImmutableDictMixin
+from .mixins import UpdateDictMixin
+
+
+def cache_control_property(key, empty, type):
+    """Return a new property object for a cache header. Useful if you
+    want to add support for a cache extension in a subclass.
+
+    .. versionchanged:: 2.0
+        Renamed from ``cache_property``.
+    """
+    return property(
+        lambda x: x._get_cache_value(key, empty, type),
+        lambda x, v: x._set_cache_value(key, v, type),
+        lambda x: x._del_cache_value(key),
+        f"accessor for {key!r}",
+    )
+
+
+class _CacheControl(UpdateDictMixin, dict):
+    """Subclass of a dict that stores values for a Cache-Control header.  It
+    has accessors for all the cache-control directives specified in RFC 2616.
+    The class does not differentiate between request and response directives.
+
+    Because the cache-control directives in the HTTP header use dashes the
+    python descriptors use underscores for that.
+
+    To get a header of the :class:`CacheControl` object again you can convert
+    the object into a string or call the :meth:`to_header` method.  If you plan
+    to subclass it and add your own items have a look at the sourcecode for
+    that class.
+
+    .. versionchanged:: 2.1.0
+        Setting int properties such as ``max_age`` will convert the
+        value to an int.
+
+    .. versionchanged:: 0.4
+
+       Setting `no_cache` or `private` to boolean `True` will set the implicit
+       none-value which is ``*``:
+
+       >>> cc = ResponseCacheControl()
+       >>> cc.no_cache = True
+       >>> cc
+       <ResponseCacheControl 'no-cache'>
+       >>> cc.no_cache
+       '*'
+       >>> cc.no_cache = None
+       >>> cc
+       <ResponseCacheControl ''>
+
+       In versions before 0.5 the behavior documented here affected the now
+       no longer existing `CacheControl` class.
+    """
+
+    no_cache = cache_control_property("no-cache", "*", None)
+    no_store = cache_control_property("no-store", None, bool)
+    max_age = cache_control_property("max-age", -1, int)
+    no_transform = cache_control_property("no-transform", None, None)
+
+    def __init__(self, values=(), on_update=None):
+        dict.__init__(self, values or ())
+        self.on_update = on_update
+        self.provided = values is not None
+
+    def _get_cache_value(self, key, empty, type):
+        """Used internally by the accessor properties."""
+        if type is bool:
+            return key in self
+        if key in self:
+            value = self[key]
+            if value is None:
+                return empty
+            elif type is not None:
+                try:
+                    value = type(value)
+                except ValueError:
+                    pass
+            return value
+        return None
+
+    def _set_cache_value(self, key, value, type):
+        """Used internally by the accessor properties."""
+        if type is bool:
+            if value:
+                self[key] = None
+            else:
+                self.pop(key, None)
+        else:
+            if value is None:
+                self.pop(key, None)
+            elif value is True:
+                self[key] = None
+            else:
+                if type is not None:
+                    self[key] = type(value)
+                else:
+                    self[key] = value
+
+    def _del_cache_value(self, key):
+        """Used internally by the accessor properties."""
+        if key in self:
+            del self[key]
+
+    def to_header(self):
+        """Convert the stored values into a cache control header."""
+        return http.dump_header(self)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        kv_str = " ".join(f"{k}={v!r}" for k, v in sorted(self.items()))
+        return f"<{type(self).__name__} {kv_str}>"
+
+    cache_property = staticmethod(cache_control_property)
+
+
+class RequestCacheControl(ImmutableDictMixin, _CacheControl):
+    """A cache control for requests.  This is immutable and gives access
+    to all the request-relevant cache control headers.
+
+    To get a header of the :class:`RequestCacheControl` object again you can
+    convert the object into a string or call the :meth:`to_header` method.  If
+    you plan to subclass it and add your own items have a look at the sourcecode
+    for that class.
+
+    .. versionchanged:: 2.1.0
+        Setting int properties such as ``max_age`` will convert the
+        value to an int.
+
+    .. versionadded:: 0.5
+       In previous versions a `CacheControl` class existed that was used
+       both for request and response.
+    """
+
+    max_stale = cache_control_property("max-stale", "*", int)
+    min_fresh = cache_control_property("min-fresh", "*", int)
+    only_if_cached = cache_control_property("only-if-cached", None, bool)
+
+
+class ResponseCacheControl(_CacheControl):
+    """A cache control for responses.  Unlike :class:`RequestCacheControl`
+    this is mutable and gives access to response-relevant cache control
+    headers.
+
+    To get a header of the :class:`ResponseCacheControl` object again you can
+    convert the object into a string or call the :meth:`to_header` method.  If
+    you plan to subclass it and add your own items have a look at the sourcecode
+    for that class.
+
+    .. versionchanged:: 2.1.1
+        ``s_maxage`` converts the value to an int.
+
+    .. versionchanged:: 2.1.0
+        Setting int properties such as ``max_age`` will convert the
+        value to an int.
+
+    .. versionadded:: 0.5
+       In previous versions a `CacheControl` class existed that was used
+       both for request and response.
+    """
+
+    public = cache_control_property("public", None, bool)
+    private = cache_control_property("private", "*", None)
+    must_revalidate = cache_control_property("must-revalidate", None, bool)
+    proxy_revalidate = cache_control_property("proxy-revalidate", None, bool)
+    s_maxage = cache_control_property("s-maxage", None, int)
+    immutable = cache_control_property("immutable", None, bool)
+
+
+# circular dependencies
+from .. import http
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.pyi
new file mode 100644
index 0000000..54ec020
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/cache_control.pyi
@@ -0,0 +1,115 @@
+from collections.abc import Callable
+from collections.abc import Iterable
+from collections.abc import Mapping
+from typing import TypeVar
+
+from .mixins import ImmutableDictMixin
+from .mixins import UpdateDictMixin
+
+T = TypeVar("T")
+_CPT = TypeVar("_CPT", str, int, bool)
+
+def cache_control_property(
+    key: str, empty: _CPT | None, type: type[_CPT]
+) -> property: ...
+
+class _CacheControl(
+    UpdateDictMixin[str, str | int | bool | None], dict[str, str | int | bool | None]
+):
+    provided: bool
+    def __init__(
+        self,
+        values: Mapping[str, str | int | bool | None]
+        | Iterable[tuple[str, str | int | bool | None]] = (),
+        on_update: Callable[[_CacheControl], None] | None = None,
+    ) -> None: ...
+    @property
+    def no_cache(self) -> bool | None: ...
+    @no_cache.setter
+    def no_cache(self, value: bool | None) -> None: ...
+    @no_cache.deleter
+    def no_cache(self) -> None: ...
+    @property
+    def no_store(self) -> bool | None: ...
+    @no_store.setter
+    def no_store(self, value: bool | None) -> None: ...
+    @no_store.deleter
+    def no_store(self) -> None: ...
+    @property
+    def max_age(self) -> int | None: ...
+    @max_age.setter
+    def max_age(self, value: int | None) -> None: ...
+    @max_age.deleter
+    def max_age(self) -> None: ...
+    @property
+    def no_transform(self) -> bool | None: ...
+    @no_transform.setter
+    def no_transform(self, value: bool | None) -> None: ...
+    @no_transform.deleter
+    def no_transform(self) -> None: ...
+    def _get_cache_value(self, key: str, empty: T | None, type: type[T]) -> T: ...
+    def _set_cache_value(self, key: str, value: T | None, type: type[T]) -> None: ...
+    def _del_cache_value(self, key: str) -> None: ...
+    def to_header(self) -> str: ...
+    @staticmethod
+    def cache_property(key: str, empty: _CPT | None, type: type[_CPT]) -> property: ...
+
+class RequestCacheControl(  # type: ignore[misc]
+    ImmutableDictMixin[str, str | int | bool | None], _CacheControl
+):
+    @property
+    def max_stale(self) -> int | None: ...
+    @max_stale.setter
+    def max_stale(self, value: int | None) -> None: ...
+    @max_stale.deleter
+    def max_stale(self) -> None: ...
+    @property
+    def min_fresh(self) -> int | None: ...
+    @min_fresh.setter
+    def min_fresh(self, value: int | None) -> None: ...
+    @min_fresh.deleter
+    def min_fresh(self) -> None: ...
+    @property
+    def only_if_cached(self) -> bool | None: ...
+    @only_if_cached.setter
+    def only_if_cached(self, value: bool | None) -> None: ...
+    @only_if_cached.deleter
+    def only_if_cached(self) -> None: ...
+
+class ResponseCacheControl(_CacheControl):
+    @property
+    def public(self) -> bool | None: ...
+    @public.setter
+    def public(self, value: bool | None) -> None: ...
+    @public.deleter
+    def public(self) -> None: ...
+    @property
+    def private(self) -> bool | None: ...
+    @private.setter
+    def private(self, value: bool | None) -> None: ...
+    @private.deleter
+    def private(self) -> None: ...
+    @property
+    def must_revalidate(self) -> bool | None: ...
+    @must_revalidate.setter
+    def must_revalidate(self, value: bool | None) -> None: ...
+    @must_revalidate.deleter
+    def must_revalidate(self) -> None: ...
+    @property
+    def proxy_revalidate(self) -> bool | None: ...
+    @proxy_revalidate.setter
+    def proxy_revalidate(self, value: bool | None) -> None: ...
+    @proxy_revalidate.deleter
+    def proxy_revalidate(self) -> None: ...
+    @property
+    def s_maxage(self) -> int | None: ...
+    @s_maxage.setter
+    def s_maxage(self, value: int | None) -> None: ...
+    @s_maxage.deleter
+    def s_maxage(self) -> None: ...
+    @property
+    def immutable(self) -> bool | None: ...
+    @immutable.setter
+    def immutable(self, value: bool | None) -> None: ...
+    @immutable.deleter
+    def immutable(self) -> None: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.py
new file mode 100644
index 0000000..dde9414
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.py
@@ -0,0 +1,94 @@
+from __future__ import annotations
+
+from .mixins import UpdateDictMixin
+
+
+def csp_property(key):
+    """Return a new property object for a content security policy header.
+    Useful if you want to add support for a csp extension in a
+    subclass.
+    """
+    return property(
+        lambda x: x._get_value(key),
+        lambda x, v: x._set_value(key, v),
+        lambda x: x._del_value(key),
+        f"accessor for {key!r}",
+    )
+
+
+class ContentSecurityPolicy(UpdateDictMixin, dict):
+    """Subclass of a dict that stores values for a Content Security Policy
+    header. It has accessors for all the level 3 policies.
+
+    Because the csp directives in the HTTP header use dashes the
+    python descriptors use underscores for that.
+
+    To get a header of the :class:`ContentSecuirtyPolicy` object again
+    you can convert the object into a string or call the
+    :meth:`to_header` method.  If you plan to subclass it and add your
+    own items have a look at the sourcecode for that class.
+
+    .. versionadded:: 1.0.0
+       Support for Content Security Policy headers was added.
+
+    """
+
+    base_uri = csp_property("base-uri")
+    child_src = csp_property("child-src")
+    connect_src = csp_property("connect-src")
+    default_src = csp_property("default-src")
+    font_src = csp_property("font-src")
+    form_action = csp_property("form-action")
+    frame_ancestors = csp_property("frame-ancestors")
+    frame_src = csp_property("frame-src")
+    img_src = csp_property("img-src")
+    manifest_src = csp_property("manifest-src")
+    media_src = csp_property("media-src")
+    navigate_to = csp_property("navigate-to")
+    object_src = csp_property("object-src")
+    prefetch_src = csp_property("prefetch-src")
+    plugin_types = csp_property("plugin-types")
+    report_to = csp_property("report-to")
+    report_uri = csp_property("report-uri")
+    sandbox = csp_property("sandbox")
+    script_src = csp_property("script-src")
+    script_src_attr = csp_property("script-src-attr")
+    script_src_elem = csp_property("script-src-elem")
+    style_src = csp_property("style-src")
+    style_src_attr = csp_property("style-src-attr")
+    style_src_elem = csp_property("style-src-elem")
+    worker_src = csp_property("worker-src")
+
+    def __init__(self, values=(), on_update=None):
+        dict.__init__(self, values or ())
+        self.on_update = on_update
+        self.provided = values is not None
+
+    def _get_value(self, key):
+        """Used internally by the accessor properties."""
+        return self.get(key)
+
+    def _set_value(self, key, value):
+        """Used internally by the accessor properties."""
+        if value is None:
+            self.pop(key, None)
+        else:
+            self[key] = value
+
+    def _del_value(self, key):
+        """Used internally by the accessor properties."""
+        if key in self:
+            del self[key]
+
+    def to_header(self):
+        """Convert the stored values into a cache control header."""
+        from ..http import dump_csp_header
+
+        return dump_csp_header(self)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        kv_str = " ".join(f"{k}={v!r}" for k, v in sorted(self.items()))
+        return f"<{type(self).__name__} {kv_str}>"
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.pyi
new file mode 100644
index 0000000..f9e2ac0
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/csp.pyi
@@ -0,0 +1,169 @@
+from collections.abc import Callable
+from collections.abc import Iterable
+from collections.abc import Mapping
+
+from .mixins import UpdateDictMixin
+
+def csp_property(key: str) -> property: ...
+
+class ContentSecurityPolicy(UpdateDictMixin[str, str], dict[str, str]):
+    @property
+    def base_uri(self) -> str | None: ...
+    @base_uri.setter
+    def base_uri(self, value: str | None) -> None: ...
+    @base_uri.deleter
+    def base_uri(self) -> None: ...
+    @property
+    def child_src(self) -> str | None: ...
+    @child_src.setter
+    def child_src(self, value: str | None) -> None: ...
+    @child_src.deleter
+    def child_src(self) -> None: ...
+    @property
+    def connect_src(self) -> str | None: ...
+    @connect_src.setter
+    def connect_src(self, value: str | None) -> None: ...
+    @connect_src.deleter
+    def connect_src(self) -> None: ...
+    @property
+    def default_src(self) -> str | None: ...
+    @default_src.setter
+    def default_src(self, value: str | None) -> None: ...
+    @default_src.deleter
+    def default_src(self) -> None: ...
+    @property
+    def font_src(self) -> str | None: ...
+    @font_src.setter
+    def font_src(self, value: str | None) -> None: ...
+    @font_src.deleter
+    def font_src(self) -> None: ...
+    @property
+    def form_action(self) -> str | None: ...
+    @form_action.setter
+    def form_action(self, value: str | None) -> None: ...
+    @form_action.deleter
+    def form_action(self) -> None: ...
+    @property
+    def frame_ancestors(self) -> str | None: ...
+    @frame_ancestors.setter
+    def frame_ancestors(self, value: str | None) -> None: ...
+    @frame_ancestors.deleter
+    def frame_ancestors(self) -> None: ...
+    @property
+    def frame_src(self) -> str | None: ...
+    @frame_src.setter
+    def frame_src(self, value: str | None) -> None: ...
+    @frame_src.deleter
+    def frame_src(self) -> None: ...
+    @property
+    def img_src(self) -> str | None: ...
+    @img_src.setter
+    def img_src(self, value: str | None) -> None: ...
+    @img_src.deleter
+    def img_src(self) -> None: ...
+    @property
+    def manifest_src(self) -> str | None: ...
+    @manifest_src.setter
+    def manifest_src(self, value: str | None) -> None: ...
+    @manifest_src.deleter
+    def manifest_src(self) -> None: ...
+    @property
+    def media_src(self) -> str | None: ...
+    @media_src.setter
+    def media_src(self, value: str | None) -> None: ...
+    @media_src.deleter
+    def media_src(self) -> None: ...
+    @property
+    def navigate_to(self) -> str | None: ...
+    @navigate_to.setter
+    def navigate_to(self, value: str | None) -> None: ...
+    @navigate_to.deleter
+    def navigate_to(self) -> None: ...
+    @property
+    def object_src(self) -> str | None: ...
+    @object_src.setter
+    def object_src(self, value: str | None) -> None: ...
+    @object_src.deleter
+    def object_src(self) -> None: ...
+    @property
+    def prefetch_src(self) -> str | None: ...
+    @prefetch_src.setter
+    def prefetch_src(self, value: str | None) -> None: ...
+    @prefetch_src.deleter
+    def prefetch_src(self) -> None: ...
+    @property
+    def plugin_types(self) -> str | None: ...
+    @plugin_types.setter
+    def plugin_types(self, value: str | None) -> None: ...
+    @plugin_types.deleter
+    def plugin_types(self) -> None: ...
+    @property
+    def report_to(self) -> str | None: ...
+    @report_to.setter
+    def report_to(self, value: str | None) -> None: ...
+    @report_to.deleter
+    def report_to(self) -> None: ...
+    @property
+    def report_uri(self) -> str | None: ...
+    @report_uri.setter
+    def report_uri(self, value: str | None) -> None: ...
+    @report_uri.deleter
+    def report_uri(self) -> None: ...
+    @property
+    def sandbox(self) -> str | None: ...
+    @sandbox.setter
+    def sandbox(self, value: str | None) -> None: ...
+    @sandbox.deleter
+    def sandbox(self) -> None: ...
+    @property
+    def script_src(self) -> str | None: ...
+    @script_src.setter
+    def script_src(self, value: str | None) -> None: ...
+    @script_src.deleter
+    def script_src(self) -> None: ...
+    @property
+    def script_src_attr(self) -> str | None: ...
+    @script_src_attr.setter
+    def script_src_attr(self, value: str | None) -> None: ...
+    @script_src_attr.deleter
+    def script_src_attr(self) -> None: ...
+    @property
+    def script_src_elem(self) -> str | None: ...
+    @script_src_elem.setter
+    def script_src_elem(self, value: str | None) -> None: ...
+    @script_src_elem.deleter
+    def script_src_elem(self) -> None: ...
+    @property
+    def style_src(self) -> str | None: ...
+    @style_src.setter
+    def style_src(self, value: str | None) -> None: ...
+    @style_src.deleter
+    def style_src(self) -> None: ...
+    @property
+    def style_src_attr(self) -> str | None: ...
+    @style_src_attr.setter
+    def style_src_attr(self, value: str | None) -> None: ...
+    @style_src_attr.deleter
+    def style_src_attr(self) -> None: ...
+    @property
+    def style_src_elem(self) -> str | None: ...
+    @style_src_elem.setter
+    def style_src_elem(self, value: str | None) -> None: ...
+    @style_src_elem.deleter
+    def style_src_elem(self) -> None: ...
+    @property
+    def worker_src(self) -> str | None: ...
+    @worker_src.setter
+    def worker_src(self, value: str | None) -> None: ...
+    @worker_src.deleter
+    def worker_src(self) -> None: ...
+    provided: bool
+    def __init__(
+        self,
+        values: Mapping[str, str] | Iterable[tuple[str, str]] = (),
+        on_update: Callable[[ContentSecurityPolicy], None] | None = None,
+    ) -> None: ...
+    def _get_value(self, key: str) -> str | None: ...
+    def _set_value(self, key: str, value: str) -> None: ...
+    def _del_value(self, key: str) -> None: ...
+    def to_header(self) -> str: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.py
new file mode 100644
index 0000000..747d996
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.py
@@ -0,0 +1,95 @@
+from __future__ import annotations
+
+from collections.abc import Collection
+
+
+class ETags(Collection):
+    """A set that can be used to check if one etag is present in a collection
+    of etags.
+    """
+
+    def __init__(self, strong_etags=None, weak_etags=None, star_tag=False):
+        if not star_tag and strong_etags:
+            self._strong = frozenset(strong_etags)
+        else:
+            self._strong = frozenset()
+
+        self._weak = frozenset(weak_etags or ())
+        self.star_tag = star_tag
+
+    def as_set(self, include_weak=False):
+        """Convert the `ETags` object into a python set.  Per default all the
+        weak etags are not part of this set."""
+        rv = set(self._strong)
+        if include_weak:
+            rv.update(self._weak)
+        return rv
+
+    def is_weak(self, etag):
+        """Check if an etag is weak."""
+        return etag in self._weak
+
+    def is_strong(self, etag):
+        """Check if an etag is strong."""
+        return etag in self._strong
+
+    def contains_weak(self, etag):
+        """Check if an etag is part of the set including weak and strong tags."""
+        return self.is_weak(etag) or self.contains(etag)
+
+    def contains(self, etag):
+        """Check if an etag is part of the set ignoring weak tags.
+        It is also possible to use the ``in`` operator.
+        """
+        if self.star_tag:
+            return True
+        return self.is_strong(etag)
+
+    def contains_raw(self, etag):
+        """When passed a quoted tag it will check if this tag is part of the
+        set.  If the tag is weak it is checked against weak and strong tags,
+        otherwise strong only."""
+        from ..http import unquote_etag
+
+        etag, weak = unquote_etag(etag)
+        if weak:
+            return self.contains_weak(etag)
+        return self.contains(etag)
+
+    def to_header(self):
+        """Convert the etags set into a HTTP header string."""
+        if self.star_tag:
+            return "*"
+        return ", ".join(
+            [f'"{x}"' for x in self._strong] + [f'W/"{x}"' for x in self._weak]
+        )
+
+    def __call__(self, etag=None, data=None, include_weak=False):
+        if [etag, data].count(None) != 1:
+            raise TypeError("either tag or data required, but at least one")
+        if etag is None:
+            from ..http import generate_etag
+
+            etag = generate_etag(data)
+        if include_weak:
+            if etag in self._weak:
+                return True
+        return etag in self._strong
+
+    def __bool__(self):
+        return bool(self.star_tag or self._strong or self._weak)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __len__(self):
+        return len(self._strong)
+
+    def __iter__(self):
+        return iter(self._strong)
+
+    def __contains__(self, etag):
+        return self.contains(etag)
+
+    def __repr__(self):
+        return f"<{type(self).__name__} {str(self)!r}>"
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.pyi
new file mode 100644
index 0000000..88e54f1
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/etag.pyi
@@ -0,0 +1,30 @@
+from collections.abc import Collection
+from collections.abc import Iterable
+from collections.abc import Iterator
+
+class ETags(Collection[str]):
+    _strong: frozenset[str]
+    _weak: frozenset[str]
+    star_tag: bool
+    def __init__(
+        self,
+        strong_etags: Iterable[str] | None = None,
+        weak_etags: Iterable[str] | None = None,
+        star_tag: bool = False,
+    ) -> None: ...
+    def as_set(self, include_weak: bool = False) -> set[str]: ...
+    def is_weak(self, etag: str) -> bool: ...
+    def is_strong(self, etag: str) -> bool: ...
+    def contains_weak(self, etag: str) -> bool: ...
+    def contains(self, etag: str) -> bool: ...
+    def contains_raw(self, etag: str) -> bool: ...
+    def to_header(self) -> str: ...
+    def __call__(
+        self,
+        etag: str | None = None,
+        data: bytes | None = None,
+        include_weak: bool = False,
+    ) -> bool: ...
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[str]: ...
+    def __contains__(self, item: str) -> bool: ...  # type: ignore
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.py
new file mode 100644
index 0000000..e878a56
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.py
@@ -0,0 +1,196 @@
+from __future__ import annotations
+
+import mimetypes
+from io import BytesIO
+from os import fsdecode
+from os import fspath
+
+from .._internal import _plain_int
+from .structures import MultiDict
+
+
+class FileStorage:
+    """The :class:`FileStorage` class is a thin wrapper over incoming files.
+    It is used by the request object to represent uploaded files.  All the
+    attributes of the wrapper stream are proxied by the file storage so
+    it's possible to do ``storage.read()`` instead of the long form
+    ``storage.stream.read()``.
+    """
+
+    def __init__(
+        self,
+        stream=None,
+        filename=None,
+        name=None,
+        content_type=None,
+        content_length=None,
+        headers=None,
+    ):
+        self.name = name
+        self.stream = stream or BytesIO()
+
+        # If no filename is provided, attempt to get the filename from
+        # the stream object. Python names special streams like
+        # ``<stderr>`` with angular brackets, skip these streams.
+        if filename is None:
+            filename = getattr(stream, "name", None)
+
+            if filename is not None:
+                filename = fsdecode(filename)
+
+            if filename and filename[0] == "<" and filename[-1] == ">":
+                filename = None
+        else:
+            filename = fsdecode(filename)
+
+        self.filename = filename
+
+        if headers is None:
+            from .headers import Headers
+
+            headers = Headers()
+        self.headers = headers
+        if content_type is not None:
+            headers["Content-Type"] = content_type
+        if content_length is not None:
+            headers["Content-Length"] = str(content_length)
+
+    def _parse_content_type(self):
+        if not hasattr(self, "_parsed_content_type"):
+            self._parsed_content_type = http.parse_options_header(self.content_type)
+
+    @property
+    def content_type(self):
+        """The content-type sent in the header.  Usually not available"""
+        return self.headers.get("content-type")
+
+    @property
+    def content_length(self):
+        """The content-length sent in the header.  Usually not available"""
+        if "content-length" in self.headers:
+            try:
+                return _plain_int(self.headers["content-length"])
+            except ValueError:
+                pass
+
+        return 0
+
+    @property
+    def mimetype(self):
+        """Like :attr:`content_type`, but without parameters (eg, without
+        charset, type etc.) and always lowercase.  For example if the content
+        type is ``text/HTML; charset=utf-8`` the mimetype would be
+        ``'text/html'``.
+
+        .. versionadded:: 0.7
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[0].lower()
+
+    @property
+    def mimetype_params(self):
+        """The mimetype parameters as dict.  For example if the content
+        type is ``text/html; charset=utf-8`` the params would be
+        ``{'charset': 'utf-8'}``.
+
+        .. versionadded:: 0.7
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[1]
+
+    def save(self, dst, buffer_size=16384):
+        """Save the file to a destination path or file object.  If the
+        destination is a file object you have to close it yourself after the
+        call.  The buffer size is the number of bytes held in memory during
+        the copy process.  It defaults to 16KB.
+
+        For secure file saving also have a look at :func:`secure_filename`.
+
+        :param dst: a filename, :class:`os.PathLike`, or open file
+            object to write to.
+        :param buffer_size: Passed as the ``length`` parameter of
+            :func:`shutil.copyfileobj`.
+
+        .. versionchanged:: 1.0
+            Supports :mod:`pathlib`.
+        """
+        from shutil import copyfileobj
+
+        close_dst = False
+
+        if hasattr(dst, "__fspath__"):
+            dst = fspath(dst)
+
+        if isinstance(dst, str):
+            dst = open(dst, "wb")
+            close_dst = True
+
+        try:
+            copyfileobj(self.stream, dst, buffer_size)
+        finally:
+            if close_dst:
+                dst.close()
+
+    def close(self):
+        """Close the underlying file if possible."""
+        try:
+            self.stream.close()
+        except Exception:
+            pass
+
+    def __bool__(self):
+        return bool(self.filename)
+
+    def __getattr__(self, name):
+        try:
+            return getattr(self.stream, name)
+        except AttributeError:
+            # SpooledTemporaryFile doesn't implement IOBase, get the
+            # attribute from its backing file instead.
+            # https://github.com/python/cpython/pull/3249
+            if hasattr(self.stream, "_file"):
+                return getattr(self.stream._file, name)
+            raise
+
+    def __iter__(self):
+        return iter(self.stream)
+
+    def __repr__(self):
+        return f"<{type(self).__name__}: {self.filename!r} ({self.content_type!r})>"
+
+
+class FileMultiDict(MultiDict):
+    """A special :class:`MultiDict` that has convenience methods to add
+    files to it.  This is used for :class:`EnvironBuilder` and generally
+    useful for unittesting.
+
+    .. versionadded:: 0.5
+    """
+
+    def add_file(self, name, file, filename=None, content_type=None):
+        """Adds a new file to the dict.  `file` can be a file name or
+        a :class:`file`-like or a :class:`FileStorage` object.
+
+        :param name: the name of the field.
+        :param file: a filename or :class:`file`-like object
+        :param filename: an optional filename
+        :param content_type: an optional content type
+        """
+        if isinstance(file, FileStorage):
+            value = file
+        else:
+            if isinstance(file, str):
+                if filename is None:
+                    filename = file
+                file = open(file, "rb")
+            if filename and content_type is None:
+                content_type = (
+                    mimetypes.guess_type(filename)[0] or "application/octet-stream"
+                )
+            value = FileStorage(file, filename, name, content_type)
+
+        self.add(name, value)
+
+
+# circular dependencies
+from .. import http
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.pyi
new file mode 100644
index 0000000..36a7ed9
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/file_storage.pyi
@@ -0,0 +1,49 @@
+from collections.abc import Iterator
+from os import PathLike
+from typing import Any
+from typing import IO
+
+from .headers import Headers
+from .structures import MultiDict
+
+class FileStorage:
+    name: str | None
+    stream: IO[bytes]
+    filename: str | None
+    headers: Headers
+    _parsed_content_type: tuple[str, dict[str, str]]
+    def __init__(
+        self,
+        stream: IO[bytes] | None = None,
+        filename: str | PathLike[str] | None = None,
+        name: str | None = None,
+        content_type: str | None = None,
+        content_length: int | None = None,
+        headers: Headers | None = None,
+    ) -> None: ...
+    def _parse_content_type(self) -> None: ...
+    @property
+    def content_type(self) -> str: ...
+    @property
+    def content_length(self) -> int: ...
+    @property
+    def mimetype(self) -> str: ...
+    @property
+    def mimetype_params(self) -> dict[str, str]: ...
+    def save(
+        self, dst: str | PathLike[str] | IO[bytes], buffer_size: int = ...
+    ) -> None: ...
+    def close(self) -> None: ...
+    def __bool__(self) -> bool: ...
+    def __getattr__(self, name: str) -> Any: ...
+    def __iter__(self) -> Iterator[bytes]: ...
+    def __repr__(self) -> str: ...
+
+class FileMultiDict(MultiDict[str, FileStorage]):
+    def add_file(
+        self,
+        name: str,
+        file: FileStorage | str | IO[bytes],
+        filename: str | None = None,
+        content_type: str | None = None,
+    ) -> None: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.py
new file mode 100644
index 0000000..d9dd655
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.py
@@ -0,0 +1,515 @@
+from __future__ import annotations
+
+import re
+import typing as t
+
+from .._internal import _missing
+from ..exceptions import BadRequestKeyError
+from .mixins import ImmutableHeadersMixin
+from .structures import iter_multi_items
+from .structures import MultiDict
+
+
+class Headers:
+    """An object that stores some headers. It has a dict-like interface,
+    but is ordered, can store the same key multiple times, and iterating
+    yields ``(key, value)`` pairs instead of only keys.
+
+    This data structure is useful if you want a nicer way to handle WSGI
+    headers which are stored as tuples in a list.
+
+    From Werkzeug 0.3 onwards, the :exc:`KeyError` raised by this class is
+    also a subclass of the :class:`~exceptions.BadRequest` HTTP exception
+    and will render a page for a ``400 BAD REQUEST`` if caught in a
+    catch-all for HTTP exceptions.
+
+    Headers is mostly compatible with the Python :class:`wsgiref.headers.Headers`
+    class, with the exception of `__getitem__`.  :mod:`wsgiref` will return
+    `None` for ``headers['missing']``, whereas :class:`Headers` will raise
+    a :class:`KeyError`.
+
+    To create a new ``Headers`` object, pass it a list, dict, or
+    other ``Headers`` object with default values. These values are
+    validated the same way values added later are.
+
+    :param defaults: The list of default values for the :class:`Headers`.
+
+    .. versionchanged:: 2.1.0
+        Default values are validated the same as values added later.
+
+    .. versionchanged:: 0.9
+       This data structure now stores unicode values similar to how the
+       multi dicts do it.  The main difference is that bytes can be set as
+       well which will automatically be latin1 decoded.
+
+    .. versionchanged:: 0.9
+       The :meth:`linked` function was removed without replacement as it
+       was an API that does not support the changes to the encoding model.
+    """
+
+    def __init__(self, defaults=None):
+        self._list = []
+        if defaults is not None:
+            self.extend(defaults)
+
+    def __getitem__(self, key, _get_mode=False):
+        if not _get_mode:
+            if isinstance(key, int):
+                return self._list[key]
+            elif isinstance(key, slice):
+                return self.__class__(self._list[key])
+        if not isinstance(key, str):
+            raise BadRequestKeyError(key)
+        ikey = key.lower()
+        for k, v in self._list:
+            if k.lower() == ikey:
+                return v
+        # micro optimization: if we are in get mode we will catch that
+        # exception one stack level down so we can raise a standard
+        # key error instead of our special one.
+        if _get_mode:
+            raise KeyError()
+        raise BadRequestKeyError(key)
+
+    def __eq__(self, other):
+        def lowered(item):
+            return (item[0].lower(),) + item[1:]
+
+        return other.__class__ is self.__class__ and set(
+            map(lowered, other._list)
+        ) == set(map(lowered, self._list))
+
+    __hash__ = None
+
+    def get(self, key, default=None, type=None):
+        """Return the default value if the requested data doesn't exist.
+        If `type` is provided and is a callable it should convert the value,
+        return it or raise a :exc:`ValueError` if that is not possible.  In
+        this case the function will return the default as if the value was not
+        found:
+
+        >>> d = Headers([('Content-Length', '42')])
+        >>> d.get('Content-Length', type=int)
+        42
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key can't
+                        be looked up.  If not further specified `None` is
+                        returned.
+        :param type: A callable that is used to cast the value in the
+                     :class:`Headers`.  If a :exc:`ValueError` is raised
+                     by this callable the default value is returned.
+
+        .. versionchanged:: 3.0
+            The ``as_bytes`` parameter was removed.
+
+        .. versionchanged:: 0.9
+            The ``as_bytes`` parameter was added.
+        """
+        try:
+            rv = self.__getitem__(key, _get_mode=True)
+        except KeyError:
+            return default
+        if type is None:
+            return rv
+        try:
+            return type(rv)
+        except ValueError:
+            return default
+
+    def getlist(self, key, type=None):
+        """Return the list of items for a given key. If that key is not in the
+        :class:`Headers`, the return value will be an empty list.  Just like
+        :meth:`get`, :meth:`getlist` accepts a `type` parameter.  All items will
+        be converted with the callable defined there.
+
+        :param key: The key to be looked up.
+        :param type: A callable that is used to cast the value in the
+                     :class:`Headers`.  If a :exc:`ValueError` is raised
+                     by this callable the value will be removed from the list.
+        :return: a :class:`list` of all the values for the key.
+
+        .. versionchanged:: 3.0
+            The ``as_bytes`` parameter was removed.
+
+        .. versionchanged:: 0.9
+            The ``as_bytes`` parameter was added.
+        """
+        ikey = key.lower()
+        result = []
+        for k, v in self:
+            if k.lower() == ikey:
+                if type is not None:
+                    try:
+                        v = type(v)
+                    except ValueError:
+                        continue
+                result.append(v)
+        return result
+
+    def get_all(self, name):
+        """Return a list of all the values for the named field.
+
+        This method is compatible with the :mod:`wsgiref`
+        :meth:`~wsgiref.headers.Headers.get_all` method.
+        """
+        return self.getlist(name)
+
+    def items(self, lower=False):
+        for key, value in self:
+            if lower:
+                key = key.lower()
+            yield key, value
+
+    def keys(self, lower=False):
+        for key, _ in self.items(lower):
+            yield key
+
+    def values(self):
+        for _, value in self.items():
+            yield value
+
+    def extend(self, *args, **kwargs):
+        """Extend headers in this object with items from another object
+        containing header items as well as keyword arguments.
+
+        To replace existing keys instead of extending, use
+        :meth:`update` instead.
+
+        If provided, the first argument can be another :class:`Headers`
+        object, a :class:`MultiDict`, :class:`dict`, or iterable of
+        pairs.
+
+        .. versionchanged:: 1.0
+            Support :class:`MultiDict`. Allow passing ``kwargs``.
+        """
+        if len(args) > 1:
+            raise TypeError(f"update expected at most 1 arguments, got {len(args)}")
+
+        if args:
+            for key, value in iter_multi_items(args[0]):
+                self.add(key, value)
+
+        for key, value in iter_multi_items(kwargs):
+            self.add(key, value)
+
+    def __delitem__(self, key, _index_operation=True):
+        if _index_operation and isinstance(key, (int, slice)):
+            del self._list[key]
+            return
+        key = key.lower()
+        new = []
+        for k, v in self._list:
+            if k.lower() != key:
+                new.append((k, v))
+        self._list[:] = new
+
+    def remove(self, key):
+        """Remove a key.
+
+        :param key: The key to be removed.
+        """
+        return self.__delitem__(key, _index_operation=False)
+
+    def pop(self, key=None, default=_missing):
+        """Removes and returns a key or index.
+
+        :param key: The key to be popped.  If this is an integer the item at
+                    that position is removed, if it's a string the value for
+                    that key is.  If the key is omitted or `None` the last
+                    item is removed.
+        :return: an item.
+        """
+        if key is None:
+            return self._list.pop()
+        if isinstance(key, int):
+            return self._list.pop(key)
+        try:
+            rv = self[key]
+            self.remove(key)
+        except KeyError:
+            if default is not _missing:
+                return default
+            raise
+        return rv
+
+    def popitem(self):
+        """Removes a key or index and returns a (key, value) item."""
+        return self.pop()
+
+    def __contains__(self, key):
+        """Check if a key is present."""
+        try:
+            self.__getitem__(key, _get_mode=True)
+        except KeyError:
+            return False
+        return True
+
+    def __iter__(self):
+        """Yield ``(key, value)`` tuples."""
+        return iter(self._list)
+
+    def __len__(self):
+        return len(self._list)
+
+    def add(self, _key, _value, **kw):
+        """Add a new header tuple to the list.
+
+        Keyword arguments can specify additional parameters for the header
+        value, with underscores converted to dashes::
+
+        >>> d = Headers()
+        >>> d.add('Content-Type', 'text/plain')
+        >>> d.add('Content-Disposition', 'attachment', filename='foo.png')
+
+        The keyword argument dumping uses :func:`dump_options_header`
+        behind the scenes.
+
+        .. versionadded:: 0.4.1
+            keyword arguments were added for :mod:`wsgiref` compatibility.
+        """
+        if kw:
+            _value = _options_header_vkw(_value, kw)
+        _value = _str_header_value(_value)
+        self._list.append((_key, _value))
+
+    def add_header(self, _key, _value, **_kw):
+        """Add a new header tuple to the list.
+
+        An alias for :meth:`add` for compatibility with the :mod:`wsgiref`
+        :meth:`~wsgiref.headers.Headers.add_header` method.
+        """
+        self.add(_key, _value, **_kw)
+
+    def clear(self):
+        """Clears all headers."""
+        del self._list[:]
+
+    def set(self, _key, _value, **kw):
+        """Remove all header tuples for `key` and add a new one.  The newly
+        added key either appears at the end of the list if there was no
+        entry or replaces the first one.
+
+        Keyword arguments can specify additional parameters for the header
+        value, with underscores converted to dashes.  See :meth:`add` for
+        more information.
+
+        .. versionchanged:: 0.6.1
+           :meth:`set` now accepts the same arguments as :meth:`add`.
+
+        :param key: The key to be inserted.
+        :param value: The value to be inserted.
+        """
+        if kw:
+            _value = _options_header_vkw(_value, kw)
+        _value = _str_header_value(_value)
+        if not self._list:
+            self._list.append((_key, _value))
+            return
+        listiter = iter(self._list)
+        ikey = _key.lower()
+        for idx, (old_key, _old_value) in enumerate(listiter):
+            if old_key.lower() == ikey:
+                # replace first occurrence
+                self._list[idx] = (_key, _value)
+                break
+        else:
+            self._list.append((_key, _value))
+            return
+        self._list[idx + 1 :] = [t for t in listiter if t[0].lower() != ikey]
+
+    def setlist(self, key, values):
+        """Remove any existing values for a header and add new ones.
+
+        :param key: The header key to set.
+        :param values: An iterable of values to set for the key.
+
+        .. versionadded:: 1.0
+        """
+        if values:
+            values_iter = iter(values)
+            self.set(key, next(values_iter))
+
+            for value in values_iter:
+                self.add(key, value)
+        else:
+            self.remove(key)
+
+    def setdefault(self, key, default):
+        """Return the first value for the key if it is in the headers,
+        otherwise set the header to the value given by ``default`` and
+        return that.
+
+        :param key: The header key to get.
+        :param default: The value to set for the key if it is not in the
+            headers.
+        """
+        if key in self:
+            return self[key]
+
+        self.set(key, default)
+        return default
+
+    def setlistdefault(self, key, default):
+        """Return the list of values for the key if it is in the
+        headers, otherwise set the header to the list of values given
+        by ``default`` and return that.
+
+        Unlike :meth:`MultiDict.setlistdefault`, modifying the returned
+        list will not affect the headers.
+
+        :param key: The header key to get.
+        :param default: An iterable of values to set for the key if it
+            is not in the headers.
+
+        .. versionadded:: 1.0
+        """
+        if key not in self:
+            self.setlist(key, default)
+
+        return self.getlist(key)
+
+    def __setitem__(self, key, value):
+        """Like :meth:`set` but also supports index/slice based setting."""
+        if isinstance(key, (slice, int)):
+            if isinstance(key, int):
+                value = [value]
+            value = [(k, _str_header_value(v)) for (k, v) in value]
+            if isinstance(key, int):
+                self._list[key] = value[0]
+            else:
+                self._list[key] = value
+        else:
+            self.set(key, value)
+
+    def update(self, *args, **kwargs):
+        """Replace headers in this object with items from another
+        headers object and keyword arguments.
+
+        To extend existing keys instead of replacing, use :meth:`extend`
+        instead.
+
+        If provided, the first argument can be another :class:`Headers`
+        object, a :class:`MultiDict`, :class:`dict`, or iterable of
+        pairs.
+
+        .. versionadded:: 1.0
+        """
+        if len(args) > 1:
+            raise TypeError(f"update expected at most 1 arguments, got {len(args)}")
+
+        if args:
+            mapping = args[0]
+
+            if isinstance(mapping, (Headers, MultiDict)):
+                for key in mapping.keys():
+                    self.setlist(key, mapping.getlist(key))
+            elif isinstance(mapping, dict):
+                for key, value in mapping.items():
+                    if isinstance(value, (list, tuple)):
+                        self.setlist(key, value)
+                    else:
+                        self.set(key, value)
+            else:
+                for key, value in mapping:
+                    self.set(key, value)
+
+        for key, value in kwargs.items():
+            if isinstance(value, (list, tuple)):
+                self.setlist(key, value)
+            else:
+                self.set(key, value)
+
+    def to_wsgi_list(self):
+        """Convert the headers into a list suitable for WSGI.
+
+        :return: list
+        """
+        return list(self)
+
+    def copy(self):
+        return self.__class__(self._list)
+
+    def __copy__(self):
+        return self.copy()
+
+    def __str__(self):
+        """Returns formatted headers suitable for HTTP transmission."""
+        strs = []
+        for key, value in self.to_wsgi_list():
+            strs.append(f"{key}: {value}")
+        strs.append("\r\n")
+        return "\r\n".join(strs)
+
+    def __repr__(self):
+        return f"{type(self).__name__}({list(self)!r})"
+
+
+def _options_header_vkw(value: str, kw: dict[str, t.Any]):
+    return http.dump_options_header(
+        value, {k.replace("_", "-"): v for k, v in kw.items()}
+    )
+
+
+_newline_re = re.compile(r"[\r\n]")
+
+
+def _str_header_value(value: t.Any) -> str:
+    if not isinstance(value, str):
+        value = str(value)
+
+    if _newline_re.search(value) is not None:
+        raise ValueError("Header values must not contain newline characters.")
+
+    return value
+
+
+class EnvironHeaders(ImmutableHeadersMixin, Headers):
+    """Read only version of the headers from a WSGI environment.  This
+    provides the same interface as `Headers` and is constructed from
+    a WSGI environment.
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for
+    HTTP exceptions.
+    """
+
+    def __init__(self, environ):
+        self.environ = environ
+
+    def __eq__(self, other):
+        return self.environ is other.environ
+
+    __hash__ = None
+
+    def __getitem__(self, key, _get_mode=False):
+        # _get_mode is a no-op for this class as there is no index but
+        # used because get() calls it.
+        if not isinstance(key, str):
+            raise KeyError(key)
+        key = key.upper().replace("-", "_")
+        if key in {"CONTENT_TYPE", "CONTENT_LENGTH"}:
+            return self.environ[key]
+        return self.environ[f"HTTP_{key}"]
+
+    def __len__(self):
+        # the iter is necessary because otherwise list calls our
+        # len which would call list again and so forth.
+        return len(list(iter(self)))
+
+    def __iter__(self):
+        for key, value in self.environ.items():
+            if key.startswith("HTTP_") and key not in {
+                "HTTP_CONTENT_TYPE",
+                "HTTP_CONTENT_LENGTH",
+            }:
+                yield key[5:].replace("_", "-").title(), value
+            elif key in {"CONTENT_TYPE", "CONTENT_LENGTH"} and value:
+                yield key.replace("_", "-").title(), value
+
+    def copy(self):
+        raise TypeError(f"cannot create {type(self).__name__!r} copies")
+
+
+# circular dependencies
+from .. import http
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.pyi
new file mode 100644
index 0000000..8650222
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/headers.pyi
@@ -0,0 +1,109 @@
+from collections.abc import Callable
+from collections.abc import Iterable
+from collections.abc import Iterator
+from collections.abc import Mapping
+from typing import Literal
+from typing import NoReturn
+from typing import overload
+from typing import TypeVar
+
+from _typeshed import SupportsKeysAndGetItem
+from _typeshed.wsgi import WSGIEnvironment
+
+from .mixins import ImmutableHeadersMixin
+
+D = TypeVar("D")
+T = TypeVar("T")
+
+class Headers(dict[str, str]):
+    _list: list[tuple[str, str]]
+    def __init__(
+        self,
+        defaults: Mapping[str, str | Iterable[str]]
+        | Iterable[tuple[str, str]]
+        | None = None,
+    ) -> None: ...
+    @overload
+    def __getitem__(self, key: str) -> str: ...
+    @overload
+    def __getitem__(self, key: int) -> tuple[str, str]: ...
+    @overload
+    def __getitem__(self, key: slice) -> Headers: ...
+    @overload
+    def __getitem__(self, key: str, _get_mode: Literal[True] = ...) -> str: ...
+    def __eq__(self, other: object) -> bool: ...
+    @overload  # type: ignore
+    def get(self, key: str, default: str) -> str: ...
+    @overload
+    def get(self, key: str, default: str | None = None) -> str | None: ...
+    @overload
+    def get(
+        self, key: str, default: T | None = None, type: Callable[[str], T] = ...
+    ) -> T | None: ...
+    @overload
+    def getlist(self, key: str) -> list[str]: ...
+    @overload
+    def getlist(self, key: str, type: Callable[[str], T]) -> list[T]: ...
+    def get_all(self, name: str) -> list[str]: ...
+    def items(  # type: ignore
+        self, lower: bool = False
+    ) -> Iterator[tuple[str, str]]: ...
+    def keys(self, lower: bool = False) -> Iterator[str]: ...  # type: ignore
+    def values(self) -> Iterator[str]: ...  # type: ignore
+    def extend(
+        self,
+        *args: Mapping[str, str | Iterable[str]] | Iterable[tuple[str, str]],
+        **kwargs: str | Iterable[str],
+    ) -> None: ...
+    @overload
+    def __delitem__(self, key: str | int | slice) -> None: ...
+    @overload
+    def __delitem__(self, key: str, _index_operation: Literal[False]) -> None: ...
+    def remove(self, key: str) -> None: ...
+    @overload  # type: ignore
+    def pop(self, key: str, default: str | None = None) -> str: ...
+    @overload
+    def pop(
+        self, key: int | None = None, default: tuple[str, str] | None = None
+    ) -> tuple[str, str]: ...
+    def popitem(self) -> tuple[str, str]: ...
+    def __contains__(self, key: str) -> bool: ...  # type: ignore
+    def has_key(self, key: str) -> bool: ...
+    def __iter__(self) -> Iterator[tuple[str, str]]: ...  # type: ignore
+    def add(self, _key: str, _value: str, **kw: str) -> None: ...
+    def _validate_value(self, value: str) -> None: ...
+    def add_header(self, _key: str, _value: str, **_kw: str) -> None: ...
+    def clear(self) -> None: ...
+    def set(self, _key: str, _value: str, **kw: str) -> None: ...
+    def setlist(self, key: str, values: Iterable[str]) -> None: ...
+    def setdefault(self, key: str, default: str) -> str: ...
+    def setlistdefault(self, key: str, default: Iterable[str]) -> None: ...
+    @overload
+    def __setitem__(self, key: str, value: str) -> None: ...
+    @overload
+    def __setitem__(self, key: int, value: tuple[str, str]) -> None: ...
+    @overload
+    def __setitem__(self, key: slice, value: Iterable[tuple[str, str]]) -> None: ...
+    @overload
+    def update(
+        self, __m: SupportsKeysAndGetItem[str, str], **kwargs: str | Iterable[str]
+    ) -> None: ...
+    @overload
+    def update(
+        self, __m: Iterable[tuple[str, str]], **kwargs: str | Iterable[str]
+    ) -> None: ...
+    @overload
+    def update(self, **kwargs: str | Iterable[str]) -> None: ...
+    def to_wsgi_list(self) -> list[tuple[str, str]]: ...
+    def copy(self) -> Headers: ...
+    def __copy__(self) -> Headers: ...
+
+class EnvironHeaders(ImmutableHeadersMixin, Headers):
+    environ: WSGIEnvironment
+    def __init__(self, environ: WSGIEnvironment) -> None: ...
+    def __eq__(self, other: object) -> bool: ...
+    def __getitem__(  # type: ignore
+        self, key: str, _get_mode: Literal[False] = False
+    ) -> str: ...
+    def __iter__(self) -> Iterator[tuple[str, str]]: ...  # type: ignore
+    def copy(self) -> NoReturn: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.py
new file mode 100644
index 0000000..2c84ca8
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.py
@@ -0,0 +1,242 @@
+from __future__ import annotations
+
+from itertools import repeat
+
+from .._internal import _missing
+
+
+def is_immutable(self):
+    raise TypeError(f"{type(self).__name__!r} objects are immutable")
+
+
+class ImmutableListMixin:
+    """Makes a :class:`list` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    _hash_cache = None
+
+    def __hash__(self):
+        if self._hash_cache is not None:
+            return self._hash_cache
+        rv = self._hash_cache = hash(tuple(self))
+        return rv
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(self),)
+
+    def __delitem__(self, key):
+        is_immutable(self)
+
+    def __iadd__(self, other):
+        is_immutable(self)
+
+    def __imul__(self, other):
+        is_immutable(self)
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    def append(self, item):
+        is_immutable(self)
+
+    def remove(self, item):
+        is_immutable(self)
+
+    def extend(self, iterable):
+        is_immutable(self)
+
+    def insert(self, pos, value):
+        is_immutable(self)
+
+    def pop(self, index=-1):
+        is_immutable(self)
+
+    def reverse(self):
+        is_immutable(self)
+
+    def sort(self, key=None, reverse=False):
+        is_immutable(self)
+
+
+class ImmutableDictMixin:
+    """Makes a :class:`dict` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    _hash_cache = None
+
+    @classmethod
+    def fromkeys(cls, keys, value=None):
+        instance = super().__new__(cls)
+        instance.__init__(zip(keys, repeat(value)))
+        return instance
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (dict(self),)
+
+    def _iter_hashitems(self):
+        return self.items()
+
+    def __hash__(self):
+        if self._hash_cache is not None:
+            return self._hash_cache
+        rv = self._hash_cache = hash(frozenset(self._iter_hashitems()))
+        return rv
+
+    def setdefault(self, key, default=None):
+        is_immutable(self)
+
+    def update(self, *args, **kwargs):
+        is_immutable(self)
+
+    def pop(self, key, default=None):
+        is_immutable(self)
+
+    def popitem(self):
+        is_immutable(self)
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    def __delitem__(self, key):
+        is_immutable(self)
+
+    def clear(self):
+        is_immutable(self)
+
+
+class ImmutableMultiDictMixin(ImmutableDictMixin):
+    """Makes a :class:`MultiDict` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(self.items(multi=True)),)
+
+    def _iter_hashitems(self):
+        return self.items(multi=True)
+
+    def add(self, key, value):
+        is_immutable(self)
+
+    def popitemlist(self):
+        is_immutable(self)
+
+    def poplist(self, key):
+        is_immutable(self)
+
+    def setlist(self, key, new_list):
+        is_immutable(self)
+
+    def setlistdefault(self, key, default_list=None):
+        is_immutable(self)
+
+
+class ImmutableHeadersMixin:
+    """Makes a :class:`Headers` immutable.  We do not mark them as
+    hashable though since the only usecase for this datastructure
+    in Werkzeug is a view on a mutable structure.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __delitem__(self, key, **kwargs):
+        is_immutable(self)
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    def set(self, _key, _value, **kwargs):
+        is_immutable(self)
+
+    def setlist(self, key, values):
+        is_immutable(self)
+
+    def add(self, _key, _value, **kwargs):
+        is_immutable(self)
+
+    def add_header(self, _key, _value, **_kwargs):
+        is_immutable(self)
+
+    def remove(self, key):
+        is_immutable(self)
+
+    def extend(self, *args, **kwargs):
+        is_immutable(self)
+
+    def update(self, *args, **kwargs):
+        is_immutable(self)
+
+    def insert(self, pos, value):
+        is_immutable(self)
+
+    def pop(self, key=None, default=_missing):
+        is_immutable(self)
+
+    def popitem(self):
+        is_immutable(self)
+
+    def setdefault(self, key, default):
+        is_immutable(self)
+
+    def setlistdefault(self, key, default):
+        is_immutable(self)
+
+
+def _calls_update(name):
+    def oncall(self, *args, **kw):
+        rv = getattr(super(UpdateDictMixin, self), name)(*args, **kw)
+
+        if self.on_update is not None:
+            self.on_update(self)
+
+        return rv
+
+    oncall.__name__ = name
+    return oncall
+
+
+class UpdateDictMixin(dict):
+    """Makes dicts call `self.on_update` on modifications.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    on_update = None
+
+    def setdefault(self, key, default=None):
+        modified = key not in self
+        rv = super().setdefault(key, default)
+        if modified and self.on_update is not None:
+            self.on_update(self)
+        return rv
+
+    def pop(self, key, default=_missing):
+        modified = key in self
+        if default is _missing:
+            rv = super().pop(key)
+        else:
+            rv = super().pop(key, default)
+        if modified and self.on_update is not None:
+            self.on_update(self)
+        return rv
+
+    __setitem__ = _calls_update("__setitem__")
+    __delitem__ = _calls_update("__delitem__")
+    clear = _calls_update("clear")
+    popitem = _calls_update("popitem")
+    update = _calls_update("update")
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.pyi
new file mode 100644
index 0000000..40453f7
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/mixins.pyi
@@ -0,0 +1,97 @@
+from collections.abc import Callable
+from collections.abc import Hashable
+from collections.abc import Iterable
+from typing import Any
+from typing import NoReturn
+from typing import overload
+from typing import SupportsIndex
+from typing import TypeVar
+
+from _typeshed import SupportsKeysAndGetItem
+
+from .headers import Headers
+
+K = TypeVar("K")
+T = TypeVar("T")
+V = TypeVar("V")
+
+def is_immutable(self: object) -> NoReturn: ...
+
+class ImmutableListMixin(list[V]):
+    _hash_cache: int | None
+    def __hash__(self) -> int: ...  # type: ignore
+    def __delitem__(self, key: SupportsIndex | slice) -> NoReturn: ...
+    def __iadd__(self, other: Any) -> NoReturn: ...  # type: ignore
+    def __imul__(self, other: SupportsIndex) -> NoReturn: ...
+    def __setitem__(self, key: int | slice, value: V) -> NoReturn: ...  # type: ignore
+    def append(self, value: V) -> NoReturn: ...
+    def remove(self, value: V) -> NoReturn: ...
+    def extend(self, values: Iterable[V]) -> NoReturn: ...
+    def insert(self, pos: SupportsIndex, value: V) -> NoReturn: ...
+    def pop(self, index: SupportsIndex = -1) -> NoReturn: ...
+    def reverse(self) -> NoReturn: ...
+    def sort(
+        self, key: Callable[[V], Any] | None = None, reverse: bool = False
+    ) -> NoReturn: ...
+
+class ImmutableDictMixin(dict[K, V]):
+    _hash_cache: int | None
+    @classmethod
+    def fromkeys(  # type: ignore
+        cls, keys: Iterable[K], value: V | None = None
+    ) -> ImmutableDictMixin[K, V]: ...
+    def _iter_hashitems(self) -> Iterable[Hashable]: ...
+    def __hash__(self) -> int: ...  # type: ignore
+    def setdefault(self, key: K, default: V | None = None) -> NoReturn: ...
+    def update(self, *args: Any, **kwargs: V) -> NoReturn: ...
+    def pop(self, key: K, default: V | None = None) -> NoReturn: ...  # type: ignore
+    def popitem(self) -> NoReturn: ...
+    def __setitem__(self, key: K, value: V) -> NoReturn: ...
+    def __delitem__(self, key: K) -> NoReturn: ...
+    def clear(self) -> NoReturn: ...
+
+class ImmutableMultiDictMixin(ImmutableDictMixin[K, V]):
+    def _iter_hashitems(self) -> Iterable[Hashable]: ...
+    def add(self, key: K, value: V) -> NoReturn: ...
+    def popitemlist(self) -> NoReturn: ...
+    def poplist(self, key: K) -> NoReturn: ...
+    def setlist(self, key: K, new_list: Iterable[V]) -> NoReturn: ...
+    def setlistdefault(
+        self, key: K, default_list: Iterable[V] | None = None
+    ) -> NoReturn: ...
+
+class ImmutableHeadersMixin(Headers):
+    def __delitem__(self, key: Any, _index_operation: bool = True) -> NoReturn: ...
+    def __setitem__(self, key: Any, value: Any) -> NoReturn: ...
+    def set(self, _key: Any, _value: Any, **kw: Any) -> NoReturn: ...
+    def setlist(self, key: Any, values: Any) -> NoReturn: ...
+    def add(self, _key: Any, _value: Any, **kw: Any) -> NoReturn: ...
+    def add_header(self, _key: Any, _value: Any, **_kw: Any) -> NoReturn: ...
+    def remove(self, key: Any) -> NoReturn: ...
+    def extend(self, *args: Any, **kwargs: Any) -> NoReturn: ...
+    def update(self, *args: Any, **kwargs: Any) -> NoReturn: ...
+    def insert(self, pos: Any, value: Any) -> NoReturn: ...
+    def pop(self, key: Any = None, default: Any = ...) -> NoReturn: ...
+    def popitem(self) -> NoReturn: ...
+    def setdefault(self, key: Any, default: Any) -> NoReturn: ...
+    def setlistdefault(self, key: Any, default: Any) -> NoReturn: ...
+
+def _calls_update(name: str) -> Callable[[UpdateDictMixin[K, V]], Any]: ...
+
+class UpdateDictMixin(dict[K, V]):
+    on_update: Callable[[UpdateDictMixin[K, V] | None, None], None]
+    def setdefault(self, key: K, default: V | None = None) -> V: ...
+    @overload
+    def pop(self, key: K) -> V: ...
+    @overload
+    def pop(self, key: K, default: V | T = ...) -> V | T: ...
+    def __setitem__(self, key: K, value: V) -> None: ...
+    def __delitem__(self, key: K) -> None: ...
+    def clear(self) -> None: ...
+    def popitem(self) -> tuple[K, V]: ...
+    @overload
+    def update(self, __m: SupportsKeysAndGetItem[K, V], **kwargs: V) -> None: ...
+    @overload
+    def update(self, __m: Iterable[tuple[K, V]], **kwargs: V) -> None: ...
+    @overload
+    def update(self, **kwargs: V) -> None: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py
new file mode 100644
index 0000000..7011ea4
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py
@@ -0,0 +1,180 @@
+from __future__ import annotations
+
+
+class IfRange:
+    """Very simple object that represents the `If-Range` header in parsed
+    form.  It will either have neither a etag or date or one of either but
+    never both.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, etag=None, date=None):
+        #: The etag parsed and unquoted.  Ranges always operate on strong
+        #: etags so the weakness information is not necessary.
+        self.etag = etag
+        #: The date in parsed format or `None`.
+        self.date = date
+
+    def to_header(self):
+        """Converts the object back into an HTTP header."""
+        if self.date is not None:
+            return http.http_date(self.date)
+        if self.etag is not None:
+            return http.quote_etag(self.etag)
+        return ""
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return f"<{type(self).__name__} {str(self)!r}>"
+
+
+class Range:
+    """Represents a ``Range`` header. All methods only support only
+    bytes as the unit. Stores a list of ranges if given, but the methods
+    only work if only one range is provided.
+
+    :raise ValueError: If the ranges provided are invalid.
+
+    .. versionchanged:: 0.15
+        The ranges passed in are validated.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, units, ranges):
+        #: The units of this range.  Usually "bytes".
+        self.units = units
+        #: A list of ``(begin, end)`` tuples for the range header provided.
+        #: The ranges are non-inclusive.
+        self.ranges = ranges
+
+        for start, end in ranges:
+            if start is None or (end is not None and (start < 0 or start >= end)):
+                raise ValueError(f"{(start, end)} is not a valid range.")
+
+    def range_for_length(self, length):
+        """If the range is for bytes, the length is not None and there is
+        exactly one range and it is satisfiable it returns a ``(start, stop)``
+        tuple, otherwise `None`.
+        """
+        if self.units != "bytes" or length is None or len(self.ranges) != 1:
+            return None
+        start, end = self.ranges[0]
+        if end is None:
+            end = length
+            if start < 0:
+                start += length
+        if http.is_byte_range_valid(start, end, length):
+            return start, min(end, length)
+        return None
+
+    def make_content_range(self, length):
+        """Creates a :class:`~werkzeug.datastructures.ContentRange` object
+        from the current range and given content length.
+        """
+        rng = self.range_for_length(length)
+        if rng is not None:
+            return ContentRange(self.units, rng[0], rng[1], length)
+        return None
+
+    def to_header(self):
+        """Converts the object back into an HTTP header."""
+        ranges = []
+        for begin, end in self.ranges:
+            if end is None:
+                ranges.append(f"{begin}-" if begin >= 0 else str(begin))
+            else:
+                ranges.append(f"{begin}-{end - 1}")
+        return f"{self.units}={','.join(ranges)}"
+
+    def to_content_range_header(self, length):
+        """Converts the object into `Content-Range` HTTP header,
+        based on given length
+        """
+        range = self.range_for_length(length)
+        if range is not None:
+            return f"{self.units} {range[0]}-{range[1] - 1}/{length}"
+        return None
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return f"<{type(self).__name__} {str(self)!r}>"
+
+
+def _callback_property(name):
+    def fget(self):
+        return getattr(self, name)
+
+    def fset(self, value):
+        setattr(self, name, value)
+        if self.on_update is not None:
+            self.on_update(self)
+
+    return property(fget, fset)
+
+
+class ContentRange:
+    """Represents the content range header.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, units, start, stop, length=None, on_update=None):
+        assert http.is_byte_range_valid(start, stop, length), "Bad range provided"
+        self.on_update = on_update
+        self.set(start, stop, length, units)
+
+    #: The units to use, usually "bytes"
+    units = _callback_property("_units")
+    #: The start point of the range or `None`.
+    start = _callback_property("_start")
+    #: The stop point of the range (non-inclusive) or `None`.  Can only be
+    #: `None` if also start is `None`.
+    stop = _callback_property("_stop")
+    #: The length of the range or `None`.
+    length = _callback_property("_length")
+
+    def set(self, start, stop, length=None, units="bytes"):
+        """Simple method to update the ranges."""
+        assert http.is_byte_range_valid(start, stop, length), "Bad range provided"
+        self._units = units
+        self._start = start
+        self._stop = stop
+        self._length = length
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def unset(self):
+        """Sets the units to `None` which indicates that the header should
+        no longer be used.
+        """
+        self.set(None, None, units=None)
+
+    def to_header(self):
+        if self.units is None:
+            return ""
+        if self.length is None:
+            length = "*"
+        else:
+            length = self.length
+        if self.start is None:
+            return f"{self.units} */{length}"
+        return f"{self.units} {self.start}-{self.stop - 1}/{length}"
+
+    def __bool__(self):
+        return self.units is not None
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return f"<{type(self).__name__} {str(self)!r}>"
+
+
+# circular dependencies
+from .. import http
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.pyi
new file mode 100644
index 0000000..f38ad69
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.pyi
@@ -0,0 +1,57 @@
+from collections.abc import Callable
+from datetime import datetime
+
+class IfRange:
+    etag: str | None
+    date: datetime | None
+    def __init__(
+        self, etag: str | None = None, date: datetime | None = None
+    ) -> None: ...
+    def to_header(self) -> str: ...
+
+class Range:
+    units: str
+    ranges: list[tuple[int, int | None]]
+    def __init__(self, units: str, ranges: list[tuple[int, int | None]]) -> None: ...
+    def range_for_length(self, length: int | None) -> tuple[int, int] | None: ...
+    def make_content_range(self, length: int | None) -> ContentRange | None: ...
+    def to_header(self) -> str: ...
+    def to_content_range_header(self, length: int | None) -> str | None: ...
+
+def _callback_property(name: str) -> property: ...
+
+class ContentRange:
+    on_update: Callable[[ContentRange], None] | None
+    def __init__(
+        self,
+        units: str | None,
+        start: int | None,
+        stop: int | None,
+        length: int | None = None,
+        on_update: Callable[[ContentRange], None] | None = None,
+    ) -> None: ...
+    @property
+    def units(self) -> str | None: ...
+    @units.setter
+    def units(self, value: str | None) -> None: ...
+    @property
+    def start(self) -> int | None: ...
+    @start.setter
+    def start(self, value: int | None) -> None: ...
+    @property
+    def stop(self) -> int | None: ...
+    @stop.setter
+    def stop(self, value: int | None) -> None: ...
+    @property
+    def length(self) -> int | None: ...
+    @length.setter
+    def length(self, value: int | None) -> None: ...
+    def set(
+        self,
+        start: int | None,
+        stop: int | None,
+        length: int | None = None,
+        units: str | None = "bytes",
+    ) -> None: ...
+    def unset(self) -> None: ...
+    def to_header(self) -> str: ...
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.py
new file mode 100644
index 0000000..4279ceb
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.py
@@ -0,0 +1,1010 @@
+from __future__ import annotations
+
+from collections.abc import MutableSet
+from copy import deepcopy
+
+from .. import exceptions
+from .._internal import _missing
+from .mixins import ImmutableDictMixin
+from .mixins import ImmutableListMixin
+from .mixins import ImmutableMultiDictMixin
+from .mixins import UpdateDictMixin
+
+
+def is_immutable(self):
+    raise TypeError(f"{type(self).__name__!r} objects are immutable")
+
+
+def iter_multi_items(mapping):
+    """Iterates over the items of a mapping yielding keys and values
+    without dropping any from more complex structures.
+    """
+    if isinstance(mapping, MultiDict):
+        yield from mapping.items(multi=True)
+    elif isinstance(mapping, dict):
+        for key, value in mapping.items():
+            if isinstance(value, (tuple, list)):
+                for v in value:
+                    yield key, v
+            else:
+                yield key, value
+    else:
+        yield from mapping
+
+
+class ImmutableList(ImmutableListMixin, list):
+    """An immutable :class:`list`.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __repr__(self):
+        return f"{type(self).__name__}({list.__repr__(self)})"
+
+
+class TypeConversionDict(dict):
+    """Works like a regular dict but the :meth:`get` method can perform
+    type conversions.  :class:`MultiDict` and :class:`CombinedMultiDict`
+    are subclasses of this class and provide the same feature.
+
+    .. versionadded:: 0.5
+    """
+
+    def get(self, key, default=None, type=None):
+        """Return the default value if the requested data doesn't exist.
+        If `type` is provided and is a callable it should convert the value,
+        return it or raise a :exc:`ValueError` if that is not possible.  In
+        this case the function will return the default as if the value was not
+        found:
+
+        >>> d = TypeConversionDict(foo='42', bar='blub')
+        >>> d.get('foo', type=int)
+        42
+        >>> d.get('bar', -1, type=int)
+        -1
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key can't
+                        be looked up.  If not further specified `None` is
+                        returned.
+        :param type: A callable that is used to cast the value in the
+                     :class:`MultiDict`.  If a :exc:`ValueError` or a
+                     :exc:`TypeError` is raised by this callable the default
+                     value is returned.
+
+        .. versionchanged:: 3.0.2
+           Returns the default value on :exc:`TypeError`, too.
+        """
+        try:
+            rv = self[key]
+        except KeyError:
+            return default
+        if type is not None:
+            try:
+                rv = type(rv)
+            except (ValueError, TypeError):
+                rv = default
+        return rv
+
+
+class ImmutableTypeConversionDict(ImmutableDictMixin, TypeConversionDict):
+    """Works like a :class:`TypeConversionDict` but does not support
+    modifications.
+
+    .. versionadded:: 0.5
+    """
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return TypeConversionDict(self)
+
+    def __copy__(self):
+        return self
+
+
+class MultiDict(TypeConversionDict):
+    """A :class:`MultiDict` is a dictionary subclass customized to deal with
+    multiple values for the same key which is for example used by the parsing
+    functions in the wrappers.  This is necessary because some HTML form
+    elements pass multiple values for the same key.
+
+    :class:`MultiDict` implements all standard dictionary methods.
+    Internally, it saves all values for a key as a list, but the standard dict
+    access methods will only return the first value for a key. If you want to
+    gain access to the other values, too, you have to use the `list` methods as
+    explained below.
+
+    Basic Usage:
+
+    >>> d = MultiDict([('a', 'b'), ('a', 'c')])
+    >>> d
+    MultiDict([('a', 'b'), ('a', 'c')])
+    >>> d['a']
+    'b'
+    >>> d.getlist('a')
+    ['b', 'c']
+    >>> 'a' in d
+    True
+
+    It behaves like a normal dict thus all dict functions will only return the
+    first value when multiple values for one key are found.
+
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
+    exceptions.
+
+    A :class:`MultiDict` can be constructed from an iterable of
+    ``(key, value)`` tuples, a dict, a :class:`MultiDict` or from Werkzeug 0.2
+    onwards some keyword parameters.
+
+    :param mapping: the initial value for the :class:`MultiDict`.  Either a
+                    regular dict, an iterable of ``(key, value)`` tuples
+                    or `None`.
+    """
+
+    def __init__(self, mapping=None):
+        if isinstance(mapping, MultiDict):
+            dict.__init__(self, ((k, vs[:]) for k, vs in mapping.lists()))
+        elif isinstance(mapping, dict):
+            tmp = {}
+            for key, value in mapping.items():
+                if isinstance(value, (tuple, list)):
+                    if len(value) == 0:
+                        continue
+                    value = list(value)
+                else:
+                    value = [value]
+                tmp[key] = value
+            dict.__init__(self, tmp)
+        else:
+            tmp = {}
+            for key, value in mapping or ():
+                tmp.setdefault(key, []).append(value)
+            dict.__init__(self, tmp)
+
+    def __getstate__(self):
+        return dict(self.lists())
+
+    def __setstate__(self, value):
+        dict.clear(self)
+        dict.update(self, value)
+
+    def __iter__(self):
+        # Work around https://bugs.python.org/issue43246.
+        # (`return super().__iter__()` also works here, which makes this look
+        # even more like it should be a no-op, yet it isn't.)
+        return dict.__iter__(self)
+
+    def __getitem__(self, key):
+        """Return the first data value for this key;
+        raises KeyError if not found.
+
+        :param key: The key to be looked up.
+        :raise KeyError: if the key does not exist.
+        """
+
+        if key in self:
+            lst = dict.__getitem__(self, key)
+            if len(lst) > 0:
+                return lst[0]
+        raise exceptions.BadRequestKeyError(key)
+
+    def __setitem__(self, key, value):
+        """Like :meth:`add` but removes an existing key first.
+
+        :param key: the key for the value.
+        :param value: the value to set.
+        """
+        dict.__setitem__(self, key, [value])
+
+    def add(self, key, value):
+        """Adds a new value for the key.
+
+        .. versionadded:: 0.6
+
+        :param key: the key for the value.
+        :param value: the value to add.
+        """
+        dict.setdefault(self, key, []).append(value)
+
+    def getlist(self, key, type=None):
+        """Return the list of items for a given key. If that key is not in the
+        `MultiDict`, the return value will be an empty list.  Just like `get`,
+        `getlist` accepts a `type` parameter.  All items will be converted
+        with the callable defined there.
+
+        :param key: The key to be looked up.
+        :param type: A callable that is used to cast the value in the
+                     :class:`MultiDict`.  If a :exc:`ValueError` is raised
+                     by this callable the value will be removed from the list.
+        :return: a :class:`list` of all the values for the key.
+        """
+        try:
+            rv = dict.__getitem__(self, key)
+        except KeyError:
+            return []
+        if type is None:
+            return list(rv)
+        result = []
+        for item in rv:
+            try:
+                result.append(type(item))
+            except ValueError:
+                pass
+        return result
+
+    def setlist(self, key, new_list):
+        """Remove the old values for a key and add new ones.  Note that the list
+        you pass the values in will be shallow-copied before it is inserted in
+        the dictionary.
+
+        >>> d = MultiDict()
+        >>> d.setlist('foo', ['1', '2'])
+        >>> d['foo']
+        '1'
+        >>> d.getlist('foo')
+        ['1', '2']
+
+        :param key: The key for which the values are set.
+        :param new_list: An iterable with the new values for the key.  Old values
+                         are removed first.
+        """
+        dict.__setitem__(self, key, list(new_list))
+
+    def setdefault(self, key, default=None):
+        """Returns the value for the key if it is in the dict, otherwise it
+        returns `default` and sets that value for `key`.
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key is not
+                        in the dict.  If not further specified it's `None`.
+        """
+        if key not in self:
+            self[key] = default
+        else:
+            default = self[key]
+        return default
+
+    def setlistdefault(self, key, default_list=None):
+        """Like `setdefault` but sets multiple values.  The list returned
+        is not a copy, but the list that is actually used internally.  This
+        means that you can put new values into the dict by appending items
+        to the list:
+
+        >>> d = MultiDict({"foo": 1})
+        >>> d.setlistdefault("foo").extend([2, 3])
+        >>> d.getlist("foo")
+        [1, 2, 3]
+
+        :param key: The key to be looked up.
+        :param default_list: An iterable of default values.  It is either copied
+                             (in case it was a list) or converted into a list
+                             before returned.
+        :return: a :class:`list`
+        """
+        if key not in self:
+            default_list = list(default_list or ())
+            dict.__setitem__(self, key, default_list)
+        else:
+            default_list = dict.__getitem__(self, key)
+        return default_list
+
+    def items(self, multi=False):
+        """Return an iterator of ``(key, value)`` pairs.
+
+        :param multi: If set to `True` the iterator returned will have a pair
+                      for each value of each key.  Otherwise it will only
+                      contain pairs for the first value of each key.
+        """
+        for key, values in dict.items(self):
+            if multi:
+                for value in values:
+                    yield key, value
+            else:
+                yield key, values[0]
+
+    def lists(self):
+        """Return a iterator of ``(key, values)`` pairs, where values is the list
+        of all values associated with the key."""
+        for key, values in dict.items(self):
+            yield key, list(values)
+
+    def values(self):
+        """Returns an iterator of the first value on every key's value list."""
+        for values in dict.values(self):
+            yield values[0]
+
+    def listvalues(self):
+        """Return an iterator of all values associated with a key.  Zipping
+        :meth:`keys` and this is the same as calling :meth:`lists`:
+
+        >>> d = MultiDict({"foo": [1, 2, 3]})
+        >>> zip(d.keys(), d.listvalues()) == d.lists()
+        True
+        """
+        return dict.values(self)
+
+    def copy(self):
+        """Return a shallow copy of this object."""
+        return self.__class__(self)
+
+    def deepcopy(self, memo=None):
+        """Return a deep copy of this object."""
+        return self.__class__(deepcopy(self.to_dict(flat=False), memo))
+
+    def to_dict(self, flat=True):
+        """Return the contents as regular dict.  If `flat` is `True` the
+        returned dict will only have the first item present, if `flat` is
+        `False` all values will be returned as lists.
+
+        :param flat: If set to `False` the dict returned will have lists
+                     with all the values in it.  Otherwise it will only
+                     contain the first value for each key.
+        :return: a :class:`dict`
+        """
+        if flat:
+            return dict(self.items())
+        return dict(self.lists())
+
+    def update(self, mapping):
+        """update() extends rather than replaces existing key lists:
+
+        >>> a = MultiDict({'x': 1})
+        >>> b = MultiDict({'x': 2, 'y': 3})
+        >>> a.update(b)
+        >>> a
+        MultiDict([('y', 3), ('x', 1), ('x', 2)])
+
+        If the value list for a key in ``other_dict`` is empty, no new values
+        will be added to the dict and the key will not be created:
+
+        >>> x = {'empty_list': []}
+        >>> y = MultiDict()
+        >>> y.update(x)
+        >>> y
+        MultiDict([])
+        """
+        for key, value in iter_multi_items(mapping):
+            MultiDict.add(self, key, value)
+
+    def pop(self, key, default=_missing):
+        """Pop the first item for a list on the dict.  Afterwards the
+        key is removed from the dict, so additional values are discarded:
+
+        >>> d = MultiDict({"foo": [1, 2, 3]})
+        >>> d.pop("foo")
+        1
+        >>> "foo" in d
+        False
+
+        :param key: the key to pop.
+        :param default: if provided the value to return if the key was
+                        not in the dictionary.
+        """
+        try:
+            lst = dict.pop(self, key)
+
+            if len(lst) == 0:
+                raise exceptions.BadRequestKeyError(key)
+
+            return lst[0]
+        except KeyError:
+            if default is not _missing:
+                return default
+
+            raise exceptions.BadRequestKeyError(key) from None
+
+    def popitem(self):
+        """Pop an item from the dict."""
+        try:
+            item = dict.popitem(self)
+
+            if len(item[1]) == 0:
+                raise exceptions.BadRequestKeyError(item[0])
+
+            return (item[0], item[1][0])
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0]) from None
+
+    def poplist(self, key):
+        """Pop the list for a key from the dict.  If the key is not in the dict
+        an empty list is returned.
+
+        .. versionchanged:: 0.5
+           If the key does no longer exist a list is returned instead of
+           raising an error.
+        """
+        return dict.pop(self, key, [])
+
+    def popitemlist(self):
+        """Pop a ``(key, list)`` tuple from the dict."""
+        try:
+            return dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0]) from None
+
+    def __copy__(self):
+        return self.copy()
+
+    def __deepcopy__(self, memo):
+        return self.deepcopy(memo=memo)
+
+    def __repr__(self):
+        return f"{type(self).__name__}({list(self.items(multi=True))!r})"
+
+
+class _omd_bucket:
+    """Wraps values in the :class:`OrderedMultiDict`.  This makes it
+    possible to keep an order over multiple different keys.  It requires
+    a lot of extra memory and slows down access a lot, but makes it
+    possible to access elements in O(1) and iterate in O(n).
+    """
+
+    __slots__ = ("prev", "key", "value", "next")
+
+    def __init__(self, omd, key, value):
+        self.prev = omd._last_bucket
+        self.key = key
+        self.value = value
+        self.next = None
+
+        if omd._first_bucket is None:
+            omd._first_bucket = self
+        if omd._last_bucket is not None:
+            omd._last_bucket.next = self
+        omd._last_bucket = self
+
+    def unlink(self, omd):
+        if self.prev:
+            self.prev.next = self.next
+        if self.next:
+            self.next.prev = self.prev
+        if omd._first_bucket is self:
+            omd._first_bucket = self.next
+        if omd._last_bucket is self:
+            omd._last_bucket = self.prev
+
+
+class OrderedMultiDict(MultiDict):
+    """Works like a regular :class:`MultiDict` but preserves the
+    order of the fields.  To convert the ordered multi dict into a
+    list you can use the :meth:`items` method and pass it ``multi=True``.
+
+    In general an :class:`OrderedMultiDict` is an order of magnitude
+    slower than a :class:`MultiDict`.
+
+    .. admonition:: note
+
+       Due to a limitation in Python you cannot convert an ordered
+       multi dict into a regular dict by using ``dict(multidict)``.
+       Instead you have to use the :meth:`to_dict` method, otherwise
+       the internal bucket objects are exposed.
+    """
+
+    def __init__(self, mapping=None):
+        dict.__init__(self)
+        self._first_bucket = self._last_bucket = None
+        if mapping is not None:
+            OrderedMultiDict.update(self, mapping)
+
+    def __eq__(self, other):
+        if not isinstance(other, MultiDict):
+            return NotImplemented
+        if isinstance(other, OrderedMultiDict):
+            iter1 = iter(self.items(multi=True))
+            iter2 = iter(other.items(multi=True))
+            try:
+                for k1, v1 in iter1:
+                    k2, v2 = next(iter2)
+                    if k1 != k2 or v1 != v2:
+                        return False
+            except StopIteration:
+                return False
+            try:
+                next(iter2)
+            except StopIteration:
+                return True
+            return False
+        if len(self) != len(other):
+            return False
+        for key, values in self.lists():
+            if other.getlist(key) != values:
+                return False
+        return True
+
+    __hash__ = None
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(self.items(multi=True)),)
+
+    def __getstate__(self):
+        return list(self.items(multi=True))
+
+    def __setstate__(self, values):
+        dict.clear(self)
+        for key, value in values:
+            self.add(key, value)
+
+    def __getitem__(self, key):
+        if key in self:
+            return dict.__getitem__(self, key)[0].value
+        raise exceptions.BadRequestKeyError(key)
+
+    def __setitem__(self, key, value):
+        self.poplist(key)
+        self.add(key, value)
+
+    def __delitem__(self, key):
+        self.pop(key)
+
+    def keys(self):
+        return (key for key, value in self.items())
+
+    def __iter__(self):
+        return iter(self.keys())
+
+    def values(self):
+        return (value for key, value in self.items())
+
+    def items(self, multi=False):
+        ptr = self._first_bucket
+        if multi:
+            while ptr is not None:
+                yield ptr.key, ptr.value
+                ptr = ptr.next
+        else:
+            returned_keys = set()
+            while ptr is not None:
+                if ptr.key not in returned_keys:
+                    returned_keys.add(ptr.key)
+                    yield ptr.key, ptr.value
+                ptr = ptr.next
+
+    def lists(self):
+        returned_keys = set()
+        ptr = self._first_bucket
+        while ptr is not None:
+            if ptr.key not in returned_keys:
+                yield ptr.key, self.getlist(ptr.key)
+                returned_keys.add(ptr.key)
+            ptr = ptr.next
+
+    def listvalues(self):
+        for _key, values in self.lists():
+            yield values
+
+    def add(self, key, value):
+        dict.setdefault(self, key, []).append(_omd_bucket(self, key, value))
+
+    def getlist(self, key, type=None):
+        try:
+            rv = dict.__getitem__(self, key)
+        except KeyError:
+            return []
+        if type is None:
+            return [x.value for x in rv]
+        result = []
+        for item in rv:
+            try:
+                result.append(type(item.value))
+            except ValueError:
+                pass
+        return result
+
+    def setlist(self, key, new_list):
+        self.poplist(key)
+        for value in new_list:
+            self.add(key, value)
+
+    def setlistdefault(self, key, default_list=None):
+        raise TypeError("setlistdefault is unsupported for ordered multi dicts")
+
+    def update(self, mapping):
+        for key, value in iter_multi_items(mapping):
+            OrderedMultiDict.add(self, key, value)
+
+    def poplist(self, key):
+        buckets = dict.pop(self, key, ())
+        for bucket in buckets:
+            bucket.unlink(self)
+        return [x.value for x in buckets]
+
+    def pop(self, key, default=_missing):
+        try:
+            buckets = dict.pop(self, key)
+        except KeyError:
+            if default is not _missing:
+                return default
+
+            raise exceptions.BadRequestKeyError(key) from None
+
+        for bucket in buckets:
+            bucket.unlink(self)
+
+        return buckets[0].value
+
+    def popitem(self):
+        try:
+            key, buckets = dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0]) from None
+
+        for bucket in buckets:
+            bucket.unlink(self)
+
+        return key, buckets[0].value
+
+    def popitemlist(self):
+        try:
+            key, buckets = dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0]) from None
+
+        for bucket in buckets:
+            bucket.unlink(self)
+
+        return key, [x.value for x in buckets]
+
+
+class CombinedMultiDict(ImmutableMultiDictMixin, MultiDict):
+    """A read only :class:`MultiDict` that you can pass multiple :class:`MultiDict`
+    instances as sequence and it will combine the return values of all wrapped
+    dicts:
+
+    >>> from werkzeug.datastructures import CombinedMultiDict, MultiDict
+    >>> post = MultiDict([('foo', 'bar')])
+    >>> get = MultiDict([('blub', 'blah')])
+    >>> combined = CombinedMultiDict([get, post])
+    >>> combined['foo']
+    'bar'
+    >>> combined['blub']
+    'blah'
+
+    This works for all read operations and will raise a `TypeError` for
+    methods that usually change data which isn't possible.
+
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
+    exceptions.
+    """
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (self.dicts,)
+
+    def __init__(self, dicts=None):
+        self.dicts = list(dicts) or []
+
+    @classmethod
+    def fromkeys(cls, keys, value=None):
+        raise TypeError(f"cannot create {cls.__name__!r} instances by fromkeys")
+
+    def __getitem__(self, key):
+        for d in self.dicts:
+            if key in d:
+                return d[key]
+        raise exceptions.BadRequestKeyError(key)
+
+    def get(self, key, default=None, type=None):
+        for d in self.dicts:
+            if key in d:
+                if type is not None:
+                    try:
+                        return type(d[key])
+                    except ValueError:
+                        continue
+                return d[key]
+        return default
+
+    def getlist(self, key, type=None):
+        rv = []
+        for d in self.dicts:
+            rv.extend(d.getlist(key, type))
+        return rv
+
+    def _keys_impl(self):
+        """This function exists so __len__ can be implemented more efficiently,
+        saving one list creation from an iterator.
+        """
+        rv = set()
+        rv.update(*self.dicts)
+        return rv
+
+    def keys(self):
+        return self._keys_impl()
+
+    def __iter__(self):
+        return iter(self.keys())
+
+    def items(self, multi=False):
+        found = set()
+        for d in self.dicts:
+            for key, value in d.items(multi):
+                if multi:
+                    yield key, value
+                elif key not in found:
+                    found.add(key)
+                    yield key, value
+
+    def values(self):
+        for _key, value in self.items():
+            yield value
+
+    def lists(self):
+        rv = {}
+        for d in self.dicts:
+            for key, values in d.lists():
+                rv.setdefault(key, []).extend(values)
+        return list(rv.items())
+
+    def listvalues(self):
+        return (x[1] for x in self.lists())
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.
+
+        This returns a :class:`MultiDict` representing the data at the
+        time of copying. The copy will no longer reflect changes to the
+        wrapped dicts.
+
+        .. versionchanged:: 0.15
+            Return a mutable :class:`MultiDict`.
+        """
+        return MultiDict(self)
+
+    def to_dict(self, flat=True):
+        """Return the contents as regular dict.  If `flat` is `True` the
+        returned dict will only have the first item present, if `flat` is
+        `False` all values will be returned as lists.
+
+        :param flat: If set to `False` the dict returned will have lists
+                     with all the values in it.  Otherwise it will only
+                     contain the first item for each key.
+        :return: a :class:`dict`
+        """
+        if flat:
+            return dict(self.items())
+
+        return dict(self.lists())
+
+    def __len__(self):
+        return len(self._keys_impl())
+
+    def __contains__(self, key):
+        for d in self.dicts:
+            if key in d:
+                return True
+        return False
+
+    def __repr__(self):
+        return f"{type(self).__name__}({self.dicts!r})"
+
+
+class ImmutableDict(ImmutableDictMixin, dict):
+    """An immutable :class:`dict`.
+
+    .. versionadded:: 0.5
+    """
+
+    def __repr__(self):
+        return f"{type(self).__name__}({dict.__repr__(self)})"
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return dict(self)
+
+    def __copy__(self):
+        return self
+
+
+class ImmutableMultiDict(ImmutableMultiDictMixin, MultiDict):
+    """An immutable :class:`MultiDict`.
+
+    .. versionadded:: 0.5
+    """
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return MultiDict(self)
+
+    def __copy__(self):
+        return self
+
+
+class ImmutableOrderedMultiDict(ImmutableMultiDictMixin, OrderedMultiDict):
+    """An immutable :class:`OrderedMultiDict`.
+
+    .. versionadded:: 0.6
+    """
+
+    def _iter_hashitems(self):
+        return enumerate(self.items(multi=True))
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return OrderedMultiDict(self)
+
+    def __copy__(self):
+        return self
+
+
+class CallbackDict(UpdateDictMixin, dict):
+    """A dict that calls a function passed every time something is changed.
+    The function is passed the dict instance.
+    """
+
+    def __init__(self, initial=None, on_update=None):
+        dict.__init__(self, initial or ())
+        self.on_update = on_update
+
+    def __repr__(self):
+        return f"<{type(self).__name__} {dict.__repr__(self)}>"
+
+
+class HeaderSet(MutableSet):
+    """Similar to the :class:`ETags` class this implements a set-like structure.
+    Unlike :class:`ETags` this is case insensitive and used for vary, allow, and
+    content-language headers.
+
+    If not constructed using the :func:`parse_set_header` function the
+    instantiation works like this:
+
+    >>> hs = HeaderSet(['foo', 'bar', 'baz'])
+    >>> hs
+    HeaderSet(['foo', 'bar', 'baz'])
+    """
+
+    def __init__(self, headers=None, on_update=None):
+        self._headers = list(headers or ())
+        self._set = {x.lower() for x in self._headers}
+        self.on_update = on_update
+
+    def add(self, header):
+        """Add a new header to the set."""
+        self.update((header,))
+
+    def remove(self, header):
+        """Remove a header from the set.  This raises an :exc:`KeyError` if the
+        header is not in the set.
+
+        .. versionchanged:: 0.5
+            In older versions a :exc:`IndexError` was raised instead of a
+            :exc:`KeyError` if the object was missing.
+
+        :param header: the header to be removed.
+        """
+        key = header.lower()
+        if key not in self._set:
+            raise KeyError(header)
+        self._set.remove(key)
+        for idx, key in enumerate(self._headers):
+            if key.lower() == header:
+                del self._headers[idx]
+                break
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def update(self, iterable):
+        """Add all the headers from the iterable to the set.
+
+        :param iterable: updates the set with the items from the iterable.
+        """
+        inserted_any = False
+        for header in iterable:
+            key = header.lower()
+            if key not in self._set:
+                self._headers.append(header)
+                self._set.add(key)
+                inserted_any = True
+        if inserted_any and self.on_update is not None:
+            self.on_update(self)
+
+    def discard(self, header):
+        """Like :meth:`remove` but ignores errors.
+
+        :param header: the header to be discarded.
+        """
+        try:
+            self.remove(header)
+        except KeyError:
+            pass
+
+    def find(self, header):
+        """Return the index of the header in the set or return -1 if not found.
+
+        :param header: the header to be looked up.
+        """
+        header = header.lower()
+        for idx, item in enumerate(self._headers):
+            if item.lower() == header:
+                return idx
+        return -1
+
+    def index(self, header):
+        """Return the index of the header in the set or raise an
+        :exc:`IndexError`.
+
+        :param header: the header to be looked up.
+        """
+        rv = self.find(header)
+        if rv < 0:
+            raise IndexError(header)
+        return rv
+
+    def clear(self):
+        """Clear the set."""
+        self._set.clear()
+        del self._headers[:]
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def as_set(self, preserve_casing=False):
+        """Return the set as real python set type.  When calling this, all
+        the items are converted to lowercase and the ordering is lost.
+
+        :param preserve_casing: if set to `True` the items in the set returned
+                                will have the original case like in the
+                                :class:`HeaderSet`, otherwise they will
+                                be lowercase.
+        """
+        if preserve_casing:
+            return set(self._headers)
+        return set(self._set)
+
+    def to_header(self):
+        """Convert the header set into an HTTP header string."""
+        return ", ".join(map(http.quote_header_value, self._headers))
+
+    def __getitem__(self, idx):
+        return self._headers[idx]
+
+    def __delitem__(self, idx):
+        rv = self._headers.pop(idx)
+        self._set.remove(rv.lower())
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def __setitem__(self, idx, value):
+        old = self._headers[idx]
+        self._set.remove(old.lower())
+        self._headers[idx] = value
+        self._set.add(value.lower())
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def __contains__(self, header):
+        return header.lower() in self._set
+
+    def __len__(self):
+        return len(self._set)
+
+    def __iter__(self):
+        return iter(self._headers)
+
+    def __bool__(self):
+        return bool(self._set)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return f"{type(self).__name__}({self._headers!r})"
+
+
+# circular dependencies
+from .. import http
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.pyi b/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.pyi
new file mode 100644
index 0000000..7086dda
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/structures.pyi
@@ -0,0 +1,206 @@
+from collections.abc import Callable
+from collections.abc import Iterable
+from collections.abc import Iterator
+from collections.abc import Mapping
+from typing import Any
+from typing import Generic
+from typing import Literal
+from typing import NoReturn
+from typing import overload
+from typing import TypeVar
+
+from .mixins import ImmutableDictMixin
+from .mixins import ImmutableListMixin
+from .mixins import ImmutableMultiDictMixin
+from .mixins import UpdateDictMixin
+
+D = TypeVar("D")
+K = TypeVar("K")
+T = TypeVar("T")
+V = TypeVar("V")
+_CD = TypeVar("_CD", bound="CallbackDict[Any, Any]")
+
+def is_immutable(self: object) -> NoReturn: ...
+def iter_multi_items(
+    mapping: Mapping[K, V | Iterable[V]] | Iterable[tuple[K, V]],
+) -> Iterator[tuple[K, V]]: ...
+
+class ImmutableList(ImmutableListMixin[V]): ...
+
+class TypeConversionDict(dict[K, V]):
+    @overload
+    def get(self, key: K, default: None = ..., type: None = ...) -> V | None: ...
+    @overload
+    def get(self, key: K, default: D, type: None = ...) -> D | V: ...
+    @overload
+    def get(self, key: K, default: D, type: Callable[[V], T]) -> D | T: ...
+    @overload
+    def get(self, key: K, type: Callable[[V], T]) -> T | None: ...
+
+class ImmutableTypeConversionDict(ImmutableDictMixin[K, V], TypeConversionDict[K, V]):
+    def copy(self) -> TypeConversionDict[K, V]: ...
+    def __copy__(self) -> ImmutableTypeConversionDict[K, V]: ...
+
+class MultiDict(TypeConversionDict[K, V]):
+    def __init__(
+        self,
+        mapping: Mapping[K, Iterable[V] | V] | Iterable[tuple[K, V]] | None = None,
+    ) -> None: ...
+    def __getitem__(self, item: K) -> V: ...
+    def __setitem__(self, key: K, value: V) -> None: ...
+    def add(self, key: K, value: V) -> None: ...
+    @overload
+    def getlist(self, key: K) -> list[V]: ...
+    @overload
+    def getlist(self, key: K, type: Callable[[V], T] = ...) -> list[T]: ...
+    def setlist(self, key: K, new_list: Iterable[V]) -> None: ...
+    def setdefault(self, key: K, default: V | None = None) -> V: ...
+    def setlistdefault(
+        self, key: K, default_list: Iterable[V] | None = None
+    ) -> list[V]: ...
+    def items(self, multi: bool = False) -> Iterator[tuple[K, V]]: ...  # type: ignore
+    def lists(self) -> Iterator[tuple[K, list[V]]]: ...
+    def values(self) -> Iterator[V]: ...  # type: ignore
+    def listvalues(self) -> Iterator[list[V]]: ...
+    def copy(self) -> MultiDict[K, V]: ...
+    def deepcopy(self, memo: Any = None) -> MultiDict[K, V]: ...
+    @overload
+    def to_dict(self) -> dict[K, V]: ...
+    @overload
+    def to_dict(self, flat: Literal[False]) -> dict[K, list[V]]: ...
+    def update(  # type: ignore
+        self, mapping: Mapping[K, Iterable[V] | V] | Iterable[tuple[K, V]]
+    ) -> None: ...
+    @overload
+    def pop(self, key: K) -> V: ...
+    @overload
+    def pop(self, key: K, default: V | T = ...) -> V | T: ...
+    def popitem(self) -> tuple[K, V]: ...
+    def poplist(self, key: K) -> list[V]: ...
+    def popitemlist(self) -> tuple[K, list[V]]: ...
+    def __copy__(self) -> MultiDict[K, V]: ...
+    def __deepcopy__(self, memo: Any) -> MultiDict[K, V]: ...
+
+class _omd_bucket(Generic[K, V]):
+    prev: _omd_bucket[K, V] | None
+    next: _omd_bucket[K, V] | None
+    key: K
+    value: V
+    def __init__(self, omd: OrderedMultiDict[K, V], key: K, value: V) -> None: ...
+    def unlink(self, omd: OrderedMultiDict[K, V]) -> None: ...
+
+class OrderedMultiDict(MultiDict[K, V]):
+    _first_bucket: _omd_bucket[K, V] | None
+    _last_bucket: _omd_bucket[K, V] | None
+    def __init__(self, mapping: Mapping[K, V] | None = None) -> None: ...
+    def __eq__(self, other: object) -> bool: ...
+    def __getitem__(self, key: K) -> V: ...
+    def __setitem__(self, key: K, value: V) -> None: ...
+    def __delitem__(self, key: K) -> None: ...
+    def keys(self) -> Iterator[K]: ...  # type: ignore
+    def __iter__(self) -> Iterator[K]: ...
+    def values(self) -> Iterator[V]: ...  # type: ignore
+    def items(self, multi: bool = False) -> Iterator[tuple[K, V]]: ...  # type: ignore
+    def lists(self) -> Iterator[tuple[K, list[V]]]: ...
+    def listvalues(self) -> Iterator[list[V]]: ...
+    def add(self, key: K, value: V) -> None: ...
+    @overload
+    def getlist(self, key: K) -> list[V]: ...
+    @overload
+    def getlist(self, key: K, type: Callable[[V], T] = ...) -> list[T]: ...
+    def setlist(self, key: K, new_list: Iterable[V]) -> None: ...
+    def setlistdefault(
+        self, key: K, default_list: Iterable[V] | None = None
+    ) -> list[V]: ...
+    def update(  # type: ignore
+        self, mapping: Mapping[K, V] | Iterable[tuple[K, V]]
+    ) -> None: ...
+    def poplist(self, key: K) -> list[V]: ...
+    @overload
+    def pop(self, key: K) -> V: ...
+    @overload
+    def pop(self, key: K, default: V | T = ...) -> V | T: ...
+    def popitem(self) -> tuple[K, V]: ...
+    def popitemlist(self) -> tuple[K, list[V]]: ...
+
+class CombinedMultiDict(ImmutableMultiDictMixin[K, V], MultiDict[K, V]):  # type: ignore
+    dicts: list[MultiDict[K, V]]
+    def __init__(self, dicts: Iterable[MultiDict[K, V]] | None) -> None: ...
+    @classmethod
+    def fromkeys(cls, keys: Any, value: Any = None) -> NoReturn: ...
+    def __getitem__(self, key: K) -> V: ...
+    @overload  # type: ignore
+    def get(self, key: K) -> V | None: ...
+    @overload
+    def get(self, key: K, default: V | T = ...) -> V | T: ...
+    @overload
+    def get(
+        self, key: K, default: T | None = None, type: Callable[[V], T] = ...
+    ) -> T | None: ...
+    @overload
+    def getlist(self, key: K) -> list[V]: ...
+    @overload
+    def getlist(self, key: K, type: Callable[[V], T] = ...) -> list[T]: ...
+    def _keys_impl(self) -> set[K]: ...
+    def keys(self) -> set[K]: ...  # type: ignore
+    def __iter__(self) -> set[K]: ...  # type: ignore
+    def items(self, multi: bool = False) -> Iterator[tuple[K, V]]: ...  # type: ignore
+    def values(self) -> Iterator[V]: ...  # type: ignore
+    def lists(self) -> Iterator[tuple[K, list[V]]]: ...
+    def listvalues(self) -> Iterator[list[V]]: ...
+    def copy(self) -> MultiDict[K, V]: ...
+    @overload
+    def to_dict(self) -> dict[K, V]: ...
+    @overload
+    def to_dict(self, flat: Literal[False]) -> dict[K, list[V]]: ...
+    def __contains__(self, key: K) -> bool: ...  # type: ignore
+    def has_key(self, key: K) -> bool: ...
+
+class ImmutableDict(ImmutableDictMixin[K, V], dict[K, V]):
+    def copy(self) -> dict[K, V]: ...
+    def __copy__(self) -> ImmutableDict[K, V]: ...
+
+class ImmutableMultiDict(  # type: ignore
+    ImmutableMultiDictMixin[K, V], MultiDict[K, V]
+):
+    def copy(self) -> MultiDict[K, V]: ...
+    def __copy__(self) -> ImmutableMultiDict[K, V]: ...
+
+class ImmutableOrderedMultiDict(  # type: ignore
+    ImmutableMultiDictMixin[K, V], OrderedMultiDict[K, V]
+):
+    def _iter_hashitems(self) -> Iterator[tuple[int, tuple[K, V]]]: ...
+    def copy(self) -> OrderedMultiDict[K, V]: ...
+    def __copy__(self) -> ImmutableOrderedMultiDict[K, V]: ...
+
+class CallbackDict(UpdateDictMixin[K, V], dict[K, V]):
+    def __init__(
+        self,
+        initial: Mapping[K, V] | Iterable[tuple[K, V]] | None = None,
+        on_update: Callable[[_CD], None] | None = None,
+    ) -> None: ...
+
+class HeaderSet(set[str]):
+    _headers: list[str]
+    _set: set[str]
+    on_update: Callable[[HeaderSet], None] | None
+    def __init__(
+        self,
+        headers: Iterable[str] | None = None,
+        on_update: Callable[[HeaderSet], None] | None = None,
+    ) -> None: ...
+    def add(self, header: str) -> None: ...
+    def remove(self, header: str) -> None: ...
+    def update(self, iterable: Iterable[str]) -> None: ...  # type: ignore
+    def discard(self, header: str) -> None: ...
+    def find(self, header: str) -> int: ...
+    def index(self, header: str) -> int: ...
+    def clear(self) -> None: ...
+    def as_set(self, preserve_casing: bool = False) -> set[str]: ...
+    def to_header(self) -> str: ...
+    def __getitem__(self, idx: int) -> str: ...
+    def __delitem__(self, idx: int) -> None: ...
+    def __setitem__(self, idx: int, value: str) -> None: ...
+    def __contains__(self, header: str) -> bool: ...  # type: ignore
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[str]: ...