diff options
author | sotech117 <michael_foiani@brown.edu> | 2025-07-31 17:27:24 -0400 |
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committer | sotech117 <michael_foiani@brown.edu> | 2025-07-31 17:27:24 -0400 |
commit | 5bf22fc7e3c392c8bd44315ca2d06d7dca7d084e (patch) | |
tree | 8dacb0f195df1c0788d36dd0064f6bbaa3143ede /venv/lib/python3.8/site-packages/flask/helpers.py | |
parent | b832d364da8c2efe09e3f75828caf73c50d01ce3 (diff) |
add code for analysis of data
Diffstat (limited to 'venv/lib/python3.8/site-packages/flask/helpers.py')
-rw-r--r-- | venv/lib/python3.8/site-packages/flask/helpers.py | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/flask/helpers.py b/venv/lib/python3.8/site-packages/flask/helpers.py new file mode 100644 index 0000000..359a842 --- /dev/null +++ b/venv/lib/python3.8/site-packages/flask/helpers.py @@ -0,0 +1,621 @@ +from __future__ import annotations + +import importlib.util +import os +import sys +import typing as t +from datetime import datetime +from functools import lru_cache +from functools import update_wrapper + +import werkzeug.utils +from werkzeug.exceptions import abort as _wz_abort +from werkzeug.utils import redirect as _wz_redirect +from werkzeug.wrappers import Response as BaseResponse + +from .globals import _cv_request +from .globals import current_app +from .globals import request +from .globals import request_ctx +from .globals import session +from .signals import message_flashed + +if t.TYPE_CHECKING: # pragma: no cover + from .wrappers import Response + + +def get_debug_flag() -> bool: + """Get whether debug mode should be enabled for the app, indicated by the + :envvar:`FLASK_DEBUG` environment variable. The default is ``False``. + """ + val = os.environ.get("FLASK_DEBUG") + return bool(val and val.lower() not in {"0", "false", "no"}) + + +def get_load_dotenv(default: bool = True) -> bool: + """Get whether the user has disabled loading default dotenv files by + setting :envvar:`FLASK_SKIP_DOTENV`. The default is ``True``, load + the files. + + :param default: What to return if the env var isn't set. + """ + val = os.environ.get("FLASK_SKIP_DOTENV") + + if not val: + return default + + return val.lower() in ("0", "false", "no") + + +def stream_with_context( + generator_or_function: t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]], +) -> t.Iterator[t.AnyStr]: + """Request contexts disappear when the response is started on the server. + This is done for efficiency reasons and to make it less likely to encounter + memory leaks with badly written WSGI middlewares. The downside is that if + you are using streamed responses, the generator cannot access request bound + information any more. + + This function however can help you keep the context around for longer:: + + from flask import stream_with_context, request, Response + + @app.route('/stream') + def streamed_response(): + @stream_with_context + def generate(): + yield 'Hello ' + yield request.args['name'] + yield '!' + return Response(generate()) + + Alternatively it can also be used around a specific generator:: + + from flask import stream_with_context, request, Response + + @app.route('/stream') + def streamed_response(): + def generate(): + yield 'Hello ' + yield request.args['name'] + yield '!' + return Response(stream_with_context(generate())) + + .. versionadded:: 0.9 + """ + try: + gen = iter(generator_or_function) # type: ignore[arg-type] + except TypeError: + + def decorator(*args: t.Any, **kwargs: t.Any) -> t.Any: + gen = generator_or_function(*args, **kwargs) # type: ignore[operator] + return stream_with_context(gen) + + return update_wrapper(decorator, generator_or_function) # type: ignore[arg-type] + + def generator() -> t.Iterator[t.AnyStr | None]: + ctx = _cv_request.get(None) + if ctx is None: + raise RuntimeError( + "'stream_with_context' can only be used when a request" + " context is active, such as in a view function." + ) + with ctx: + # Dummy sentinel. Has to be inside the context block or we're + # not actually keeping the context around. + yield None + + # The try/finally is here so that if someone passes a WSGI level + # iterator in we're still running the cleanup logic. Generators + # don't need that because they are closed on their destruction + # automatically. + try: + yield from gen + finally: + if hasattr(gen, "close"): + gen.close() + + # The trick is to start the generator. Then the code execution runs until + # the first dummy None is yielded at which point the context was already + # pushed. This item is discarded. Then when the iteration continues the + # real generator is executed. + wrapped_g = generator() + next(wrapped_g) + return wrapped_g # type: ignore[return-value] + + +def make_response(*args: t.Any) -> Response: + """Sometimes it is necessary to set additional headers in a view. Because + views do not have to return response objects but can return a value that + is converted into a response object by Flask itself, it becomes tricky to + add headers to it. This function can be called instead of using a return + and you will get a response object which you can use to attach headers. + + If view looked like this and you want to add a new header:: + + def index(): + return render_template('index.html', foo=42) + + You can now do something like this:: + + def index(): + response = make_response(render_template('index.html', foo=42)) + response.headers['X-Parachutes'] = 'parachutes are cool' + return response + + This function accepts the very same arguments you can return from a + view function. This for example creates a response with a 404 error + code:: + + response = make_response(render_template('not_found.html'), 404) + + The other use case of this function is to force the return value of a + view function into a response which is helpful with view + decorators:: + + response = make_response(view_function()) + response.headers['X-Parachutes'] = 'parachutes are cool' + + Internally this function does the following things: + + - if no arguments are passed, it creates a new response argument + - if one argument is passed, :meth:`flask.Flask.make_response` + is invoked with it. + - if more than one argument is passed, the arguments are passed + to the :meth:`flask.Flask.make_response` function as tuple. + + .. versionadded:: 0.6 + """ + if not args: + return current_app.response_class() + if len(args) == 1: + args = args[0] + return current_app.make_response(args) + + +def url_for( + endpoint: str, + *, + _anchor: str | None = None, + _method: str | None = None, + _scheme: str | None = None, + _external: bool | None = None, + **values: t.Any, +) -> str: + """Generate a URL to the given endpoint with the given values. + + This requires an active request or application context, and calls + :meth:`current_app.url_for() <flask.Flask.url_for>`. See that method + for full documentation. + + :param endpoint: The endpoint name associated with the URL to + generate. If this starts with a ``.``, the current blueprint + name (if any) will be used. + :param _anchor: If given, append this as ``#anchor`` to the URL. + :param _method: If given, generate the URL associated with this + method for the endpoint. + :param _scheme: If given, the URL will have this scheme if it is + external. + :param _external: If given, prefer the URL to be internal (False) or + require it to be external (True). External URLs include the + scheme and domain. When not in an active request, URLs are + external by default. + :param values: Values to use for the variable parts of the URL rule. + Unknown keys are appended as query string arguments, like + ``?a=b&c=d``. + + .. versionchanged:: 2.2 + Calls ``current_app.url_for``, allowing an app to override the + behavior. + + .. versionchanged:: 0.10 + The ``_scheme`` parameter was added. + + .. versionchanged:: 0.9 + The ``_anchor`` and ``_method`` parameters were added. + + .. versionchanged:: 0.9 + Calls ``app.handle_url_build_error`` on build errors. + """ + return current_app.url_for( + endpoint, + _anchor=_anchor, + _method=_method, + _scheme=_scheme, + _external=_external, + **values, + ) + + +def redirect( + location: str, code: int = 302, Response: type[BaseResponse] | None = None +) -> BaseResponse: + """Create a redirect response object. + + If :data:`~flask.current_app` is available, it will use its + :meth:`~flask.Flask.redirect` method, otherwise it will use + :func:`werkzeug.utils.redirect`. + + :param location: The URL to redirect to. + :param code: The status code for the redirect. + :param Response: The response class to use. Not used when + ``current_app`` is active, which uses ``app.response_class``. + + .. versionadded:: 2.2 + Calls ``current_app.redirect`` if available instead of always + using Werkzeug's default ``redirect``. + """ + if current_app: + return current_app.redirect(location, code=code) + + return _wz_redirect(location, code=code, Response=Response) + + +def abort(code: int | BaseResponse, *args: t.Any, **kwargs: t.Any) -> t.NoReturn: + """Raise an :exc:`~werkzeug.exceptions.HTTPException` for the given + status code. + + If :data:`~flask.current_app` is available, it will call its + :attr:`~flask.Flask.aborter` object, otherwise it will use + :func:`werkzeug.exceptions.abort`. + + :param code: The status code for the exception, which must be + registered in ``app.aborter``. + :param args: Passed to the exception. + :param kwargs: Passed to the exception. + + .. versionadded:: 2.2 + Calls ``current_app.aborter`` if available instead of always + using Werkzeug's default ``abort``. + """ + if current_app: + current_app.aborter(code, *args, **kwargs) + + _wz_abort(code, *args, **kwargs) + + +def get_template_attribute(template_name: str, attribute: str) -> t.Any: + """Loads a macro (or variable) a template exports. This can be used to + invoke a macro from within Python code. If you for example have a + template named :file:`_cider.html` with the following contents: + + .. sourcecode:: html+jinja + + {% macro hello(name) %}Hello {{ name }}!{% endmacro %} + + You can access this from Python code like this:: + + hello = get_template_attribute('_cider.html', 'hello') + return hello('World') + + .. versionadded:: 0.2 + + :param template_name: the name of the template + :param attribute: the name of the variable of macro to access + """ + return getattr(current_app.jinja_env.get_template(template_name).module, attribute) + + +def flash(message: str, category: str = "message") -> None: + """Flashes a message to the next request. In order to remove the + flashed message from the session and to display it to the user, + the template has to call :func:`get_flashed_messages`. + + .. versionchanged:: 0.3 + `category` parameter added. + + :param message: the message to be flashed. + :param category: the category for the message. The following values + are recommended: ``'message'`` for any kind of message, + ``'error'`` for errors, ``'info'`` for information + messages and ``'warning'`` for warnings. However any + kind of string can be used as category. + """ + # Original implementation: + # + # session.setdefault('_flashes', []).append((category, message)) + # + # This assumed that changes made to mutable structures in the session are + # always in sync with the session object, which is not true for session + # implementations that use external storage for keeping their keys/values. + flashes = session.get("_flashes", []) + flashes.append((category, message)) + session["_flashes"] = flashes + app = current_app._get_current_object() # type: ignore + message_flashed.send( + app, + _async_wrapper=app.ensure_sync, + message=message, + category=category, + ) + + +def get_flashed_messages( + with_categories: bool = False, category_filter: t.Iterable[str] = () +) -> list[str] | list[tuple[str, str]]: + """Pulls all flashed messages from the session and returns them. + Further calls in the same request to the function will return + the same messages. By default just the messages are returned, + but when `with_categories` is set to ``True``, the return value will + be a list of tuples in the form ``(category, message)`` instead. + + Filter the flashed messages to one or more categories by providing those + categories in `category_filter`. This allows rendering categories in + separate html blocks. The `with_categories` and `category_filter` + arguments are distinct: + + * `with_categories` controls whether categories are returned with message + text (``True`` gives a tuple, where ``False`` gives just the message text). + * `category_filter` filters the messages down to only those matching the + provided categories. + + See :doc:`/patterns/flashing` for examples. + + .. versionchanged:: 0.3 + `with_categories` parameter added. + + .. versionchanged:: 0.9 + `category_filter` parameter added. + + :param with_categories: set to ``True`` to also receive categories. + :param category_filter: filter of categories to limit return values. Only + categories in the list will be returned. + """ + flashes = request_ctx.flashes + if flashes is None: + flashes = session.pop("_flashes") if "_flashes" in session else [] + request_ctx.flashes = flashes + if category_filter: + flashes = list(filter(lambda f: f[0] in category_filter, flashes)) + if not with_categories: + return [x[1] for x in flashes] + return flashes + + +def _prepare_send_file_kwargs(**kwargs: t.Any) -> dict[str, t.Any]: + if kwargs.get("max_age") is None: + kwargs["max_age"] = current_app.get_send_file_max_age + + kwargs.update( + environ=request.environ, + use_x_sendfile=current_app.config["USE_X_SENDFILE"], + response_class=current_app.response_class, + _root_path=current_app.root_path, # type: ignore + ) + return kwargs + + +def send_file( + path_or_file: os.PathLike[t.AnyStr] | str | t.BinaryIO, + mimetype: str | None = None, + as_attachment: bool = False, + download_name: str | None = None, + conditional: bool = True, + etag: bool | str = True, + last_modified: datetime | int | float | None = None, + max_age: None | (int | t.Callable[[str | None], int | None]) = None, +) -> Response: + """Send the contents of a file to the client. + + The first argument can be a file path or a file-like object. Paths + are preferred in most cases because Werkzeug can manage the file and + get extra information from the path. Passing a file-like object + requires that the file is opened in binary mode, and is mostly + useful when building a file in memory with :class:`io.BytesIO`. + + Never pass file paths provided by a user. The path is assumed to be + trusted, so a user could craft a path to access a file you didn't + intend. Use :func:`send_from_directory` to safely serve + user-requested paths from within a directory. + + If the WSGI server sets a ``file_wrapper`` in ``environ``, it is + used, otherwise Werkzeug's built-in wrapper is used. Alternatively, + if the HTTP server supports ``X-Sendfile``, configuring Flask with + ``USE_X_SENDFILE = True`` will tell the server to send the given + path, which is much more efficient than reading it in Python. + + :param path_or_file: The path to the file to send, relative to the + current working directory if a relative path is given. + Alternatively, a file-like object opened in binary mode. Make + sure the file pointer is seeked to the start of the data. + :param mimetype: The MIME type to send for the file. If not + provided, it will try to detect it from the file name. + :param as_attachment: Indicate to a browser that it should offer to + save the file instead of displaying it. + :param download_name: The default name browsers will use when saving + the file. Defaults to the passed file name. + :param conditional: Enable conditional and range responses based on + request headers. Requires passing a file path and ``environ``. + :param etag: Calculate an ETag for the file, which requires passing + a file path. Can also be a string to use instead. + :param last_modified: The last modified time to send for the file, + in seconds. If not provided, it will try to detect it from the + file path. + :param max_age: How long the client should cache the file, in + seconds. If set, ``Cache-Control`` will be ``public``, otherwise + it will be ``no-cache`` to prefer conditional caching. + + .. versionchanged:: 2.0 + ``download_name`` replaces the ``attachment_filename`` + parameter. If ``as_attachment=False``, it is passed with + ``Content-Disposition: inline`` instead. + + .. versionchanged:: 2.0 + ``max_age`` replaces the ``cache_timeout`` parameter. + ``conditional`` is enabled and ``max_age`` is not set by + default. + + .. versionchanged:: 2.0 + ``etag`` replaces the ``add_etags`` parameter. It can be a + string to use instead of generating one. + + .. versionchanged:: 2.0 + Passing a file-like object that inherits from + :class:`~io.TextIOBase` will raise a :exc:`ValueError` rather + than sending an empty file. + + .. versionadded:: 2.0 + Moved the implementation to Werkzeug. This is now a wrapper to + pass some Flask-specific arguments. + + .. versionchanged:: 1.1 + ``filename`` may be a :class:`~os.PathLike` object. + + .. versionchanged:: 1.1 + Passing a :class:`~io.BytesIO` object supports range requests. + + .. versionchanged:: 1.0.3 + Filenames are encoded with ASCII instead of Latin-1 for broader + compatibility with WSGI servers. + + .. versionchanged:: 1.0 + UTF-8 filenames as specified in :rfc:`2231` are supported. + + .. versionchanged:: 0.12 + The filename is no longer automatically inferred from file + objects. If you want to use automatic MIME and etag support, + pass a filename via ``filename_or_fp`` or + ``attachment_filename``. + + .. versionchanged:: 0.12 + ``attachment_filename`` is preferred over ``filename`` for MIME + detection. + + .. versionchanged:: 0.9 + ``cache_timeout`` defaults to + :meth:`Flask.get_send_file_max_age`. + + .. versionchanged:: 0.7 + MIME guessing and etag support for file-like objects was + removed because it was unreliable. Pass a filename if you are + able to, otherwise attach an etag yourself. + + .. versionchanged:: 0.5 + The ``add_etags``, ``cache_timeout`` and ``conditional`` + parameters were added. The default behavior is to add etags. + + .. versionadded:: 0.2 + """ + return werkzeug.utils.send_file( # type: ignore[return-value] + **_prepare_send_file_kwargs( + path_or_file=path_or_file, + environ=request.environ, + mimetype=mimetype, + as_attachment=as_attachment, + download_name=download_name, + conditional=conditional, + etag=etag, + last_modified=last_modified, + max_age=max_age, + ) + ) + + +def send_from_directory( + directory: os.PathLike[str] | str, + path: os.PathLike[str] | str, + **kwargs: t.Any, +) -> Response: + """Send a file from within a directory using :func:`send_file`. + + .. code-block:: python + + @app.route("/uploads/<path:name>") + def download_file(name): + return send_from_directory( + app.config['UPLOAD_FOLDER'], name, as_attachment=True + ) + + This is a secure way to serve files from a folder, such as static + files or uploads. Uses :func:`~werkzeug.security.safe_join` to + ensure the path coming from the client is not maliciously crafted to + point outside the specified directory. + + If the final path does not point to an existing regular file, + raises a 404 :exc:`~werkzeug.exceptions.NotFound` error. + + :param directory: The directory that ``path`` must be located under, + relative to the current application's root path. + :param path: The path to the file to send, relative to + ``directory``. + :param kwargs: Arguments to pass to :func:`send_file`. + + .. versionchanged:: 2.0 + ``path`` replaces the ``filename`` parameter. + + .. versionadded:: 2.0 + Moved the implementation to Werkzeug. This is now a wrapper to + pass some Flask-specific arguments. + + .. versionadded:: 0.5 + """ + return werkzeug.utils.send_from_directory( # type: ignore[return-value] + directory, path, **_prepare_send_file_kwargs(**kwargs) + ) + + +def get_root_path(import_name: str) -> str: + """Find the root path of a package, or the path that contains a + module. If it cannot be found, returns the current working + directory. + + Not to be confused with the value returned by :func:`find_package`. + + :meta private: + """ + # Module already imported and has a file attribute. Use that first. + mod = sys.modules.get(import_name) + + if mod is not None and hasattr(mod, "__file__") and mod.__file__ is not None: + return os.path.dirname(os.path.abspath(mod.__file__)) + + # Next attempt: check the loader. + try: + spec = importlib.util.find_spec(import_name) + + if spec is None: + raise ValueError + except (ImportError, ValueError): + loader = None + else: + loader = spec.loader + + # Loader does not exist or we're referring to an unloaded main + # module or a main module without path (interactive sessions), go + # with the current working directory. + if loader is None: + return os.getcwd() + + if hasattr(loader, "get_filename"): + filepath = loader.get_filename(import_name) + else: + # Fall back to imports. + __import__(import_name) + mod = sys.modules[import_name] + filepath = getattr(mod, "__file__", None) + + # If we don't have a file path it might be because it is a + # namespace package. In this case pick the root path from the + # first module that is contained in the package. + if filepath is None: + raise RuntimeError( + "No root path can be found for the provided module" + f" {import_name!r}. This can happen because the module" + " came from an import hook that does not provide file" + " name information or because it's a namespace package." + " In this case the root path needs to be explicitly" + " provided." + ) + + # filepath is import_name.py for a module, or __init__.py for a package. + return os.path.dirname(os.path.abspath(filepath)) # type: ignore[no-any-return] + + +@lru_cache(maxsize=None) +def _split_blueprint_path(name: str) -> list[str]: + out: list[str] = [name] + + if "." in name: + out.extend(_split_blueprint_path(name.rpartition(".")[0])) + + return out |