691 lines
24 KiB
Python
691 lines
24 KiB
Python
from __future__ import annotations
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import io
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import mimetypes
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import os
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import pkgutil
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import re
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import sys
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import typing as t
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import unicodedata
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from datetime import datetime
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from time import time
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from urllib.parse import quote
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from zlib import adler32
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from markupsafe import escape
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from ._internal import _DictAccessorProperty
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from ._internal import _missing
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from ._internal import _TAccessorValue
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from .datastructures import Headers
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from .exceptions import NotFound
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from .exceptions import RequestedRangeNotSatisfiable
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from .security import safe_join
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from .wsgi import wrap_file
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if t.TYPE_CHECKING:
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from _typeshed.wsgi import WSGIEnvironment
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from .wrappers.request import Request
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from .wrappers.response import Response
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_T = t.TypeVar("_T")
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_entity_re = re.compile(r"&([^;]+);")
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_filename_ascii_strip_re = re.compile(r"[^A-Za-z0-9_.-]")
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_windows_device_files = {
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"CON",
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"PRN",
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"AUX",
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"NUL",
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*(f"COM{i}" for i in range(10)),
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*(f"LPT{i}" for i in range(10)),
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}
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class cached_property(property, t.Generic[_T]):
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"""A :func:`property` that is only evaluated once. Subsequent access
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returns the cached value. Setting the property sets the cached
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value. Deleting the property clears the cached value, accessing it
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again will evaluate it again.
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.. code-block:: python
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class Example:
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@cached_property
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def value(self):
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# calculate something important here
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return 42
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e = Example()
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e.value # evaluates
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e.value # uses cache
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e.value = 16 # sets cache
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del e.value # clears cache
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If the class defines ``__slots__``, it must add ``_cache_{name}`` as
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a slot. Alternatively, it can add ``__dict__``, but that's usually
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not desirable.
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.. versionchanged:: 2.1
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Works with ``__slots__``.
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.. versionchanged:: 2.0
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``del obj.name`` clears the cached value.
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"""
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def __init__(
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self,
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fget: t.Callable[[t.Any], _T],
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name: str | None = None,
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doc: str | None = None,
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) -> None:
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super().__init__(fget, doc=doc)
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self.__name__ = name or fget.__name__
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self.slot_name = f"_cache_{self.__name__}"
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self.__module__ = fget.__module__
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def __set__(self, obj: object, value: _T) -> None:
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if hasattr(obj, "__dict__"):
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obj.__dict__[self.__name__] = value
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else:
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setattr(obj, self.slot_name, value)
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def __get__(self, obj: object, type: type = None) -> _T: # type: ignore
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if obj is None:
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return self # type: ignore
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obj_dict = getattr(obj, "__dict__", None)
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if obj_dict is not None:
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value: _T = obj_dict.get(self.__name__, _missing)
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else:
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value = getattr(obj, self.slot_name, _missing) # type: ignore[arg-type]
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if value is _missing:
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value = self.fget(obj) # type: ignore
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if obj_dict is not None:
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obj.__dict__[self.__name__] = value
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else:
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setattr(obj, self.slot_name, value)
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return value
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def __delete__(self, obj: object) -> None:
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if hasattr(obj, "__dict__"):
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del obj.__dict__[self.__name__]
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else:
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setattr(obj, self.slot_name, _missing)
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class environ_property(_DictAccessorProperty[_TAccessorValue]):
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"""Maps request attributes to environment variables. This works not only
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for the Werkzeug request object, but also any other class with an
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environ attribute:
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>>> class Test(object):
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... environ = {'key': 'value'}
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... test = environ_property('key')
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>>> var = Test()
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>>> var.test
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'value'
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If you pass it a second value it's used as default if the key does not
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exist, the third one can be a converter that takes a value and converts
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it. If it raises :exc:`ValueError` or :exc:`TypeError` the default value
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is used. If no default value is provided `None` is used.
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Per default the property is read only. You have to explicitly enable it
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by passing ``read_only=False`` to the constructor.
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"""
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read_only = True
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def lookup(self, obj: Request) -> WSGIEnvironment:
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return obj.environ
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class header_property(_DictAccessorProperty[_TAccessorValue]):
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"""Like `environ_property` but for headers."""
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def lookup(self, obj: Request | Response) -> Headers:
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return obj.headers
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# https://cgit.freedesktop.org/xdg/shared-mime-info/tree/freedesktop.org.xml.in
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# https://www.iana.org/assignments/media-types/media-types.xhtml
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# Types listed in the XDG mime info that have a charset in the IANA registration.
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_charset_mimetypes = {
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"application/ecmascript",
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"application/javascript",
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"application/sql",
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"application/xml",
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"application/xml-dtd",
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"application/xml-external-parsed-entity",
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}
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def get_content_type(mimetype: str, charset: str) -> str:
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"""Returns the full content type string with charset for a mimetype.
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If the mimetype represents text, the charset parameter will be
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appended, otherwise the mimetype is returned unchanged.
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:param mimetype: The mimetype to be used as content type.
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:param charset: The charset to be appended for text mimetypes.
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:return: The content type.
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.. versionchanged:: 0.15
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Any type that ends with ``+xml`` gets a charset, not just those
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that start with ``application/``. Known text types such as
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``application/javascript`` are also given charsets.
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"""
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if (
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mimetype.startswith("text/")
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or mimetype in _charset_mimetypes
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or mimetype.endswith("+xml")
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):
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mimetype += f"; charset={charset}"
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return mimetype
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def secure_filename(filename: str) -> str:
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r"""Pass it a filename and it will return a secure version of it. This
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filename can then safely be stored on a regular file system and passed
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to :func:`os.path.join`. The filename returned is an ASCII only string
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for maximum portability.
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On windows systems the function also makes sure that the file is not
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named after one of the special device files.
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>>> secure_filename("My cool movie.mov")
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'My_cool_movie.mov'
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>>> secure_filename("../../../etc/passwd")
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'etc_passwd'
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>>> secure_filename('i contain cool \xfcml\xe4uts.txt')
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'i_contain_cool_umlauts.txt'
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The function might return an empty filename. It's your responsibility
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to ensure that the filename is unique and that you abort or
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generate a random filename if the function returned an empty one.
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.. versionadded:: 0.5
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:param filename: the filename to secure
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"""
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filename = unicodedata.normalize("NFKD", filename)
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filename = filename.encode("ascii", "ignore").decode("ascii")
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for sep in os.sep, os.path.altsep:
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if sep:
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filename = filename.replace(sep, " ")
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filename = str(_filename_ascii_strip_re.sub("", "_".join(filename.split()))).strip(
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"._"
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)
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# on nt a couple of special files are present in each folder. We
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# have to ensure that the target file is not such a filename. In
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# this case we prepend an underline
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if (
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os.name == "nt"
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and filename
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and filename.split(".")[0].upper() in _windows_device_files
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):
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filename = f"_{filename}"
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return filename
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def redirect(
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location: str, code: int = 302, Response: type[Response] | None = None
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) -> Response:
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"""Returns a response object (a WSGI application) that, if called,
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redirects the client to the target location. Supported codes are
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301, 302, 303, 305, 307, and 308. 300 is not supported because
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it's not a real redirect and 304 because it's the answer for a
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request with a request with defined If-Modified-Since headers.
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.. versionadded:: 0.6
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The location can now be a unicode string that is encoded using
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the :func:`iri_to_uri` function.
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.. versionadded:: 0.10
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The class used for the Response object can now be passed in.
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:param location: the location the response should redirect to.
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:param code: the redirect status code. defaults to 302.
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:param class Response: a Response class to use when instantiating a
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response. The default is :class:`werkzeug.wrappers.Response` if
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unspecified.
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"""
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if Response is None:
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from .wrappers import Response
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html_location = escape(location)
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response = Response( # type: ignore[misc]
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"<!doctype html>\n"
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"<html lang=en>\n"
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"<title>Redirecting...</title>\n"
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"<h1>Redirecting...</h1>\n"
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"<p>You should be redirected automatically to the target URL: "
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f'<a href="{html_location}">{html_location}</a>. If not, click the link.\n',
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code,
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mimetype="text/html",
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)
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response.headers["Location"] = location
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return response
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def append_slash_redirect(environ: WSGIEnvironment, code: int = 308) -> Response:
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"""Redirect to the current URL with a slash appended.
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If the current URL is ``/user/42``, the redirect URL will be
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``42/``. When joined to the current URL during response
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processing or by the browser, this will produce ``/user/42/``.
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The behavior is undefined if the path ends with a slash already. If
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called unconditionally on a URL, it may produce a redirect loop.
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:param environ: Use the path and query from this WSGI environment
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to produce the redirect URL.
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:param code: the status code for the redirect.
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.. versionchanged:: 2.1
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Produce a relative URL that only modifies the last segment.
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Relevant when the current path has multiple segments.
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.. versionchanged:: 2.1
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The default status code is 308 instead of 301. This preserves
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the request method and body.
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"""
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tail = environ["PATH_INFO"].rpartition("/")[2]
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if not tail:
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new_path = "./"
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else:
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new_path = f"{tail}/"
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query_string = environ.get("QUERY_STRING")
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if query_string:
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new_path = f"{new_path}?{query_string}"
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return redirect(new_path, code)
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def send_file(
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path_or_file: os.PathLike | str | t.IO[bytes],
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environ: WSGIEnvironment,
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mimetype: str | None = None,
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as_attachment: bool = False,
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download_name: str | None = None,
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conditional: bool = True,
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etag: bool | str = True,
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last_modified: datetime | int | float | None = None,
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max_age: None | (int | t.Callable[[str | None], int | None]) = None,
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use_x_sendfile: bool = False,
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response_class: type[Response] | None = None,
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_root_path: os.PathLike | str | None = None,
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) -> Response:
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"""Send the contents of a file to the client.
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The first argument can be a file path or a file-like object. Paths
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are preferred in most cases because Werkzeug can manage the file and
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get extra information from the path. Passing a file-like object
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requires that the file is opened in binary mode, and is mostly
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useful when building a file in memory with :class:`io.BytesIO`.
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Never pass file paths provided by a user. The path is assumed to be
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trusted, so a user could craft a path to access a file you didn't
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intend. Use :func:`send_from_directory` to safely serve user-provided paths.
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If the WSGI server sets a ``file_wrapper`` in ``environ``, it is
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used, otherwise Werkzeug's built-in wrapper is used. Alternatively,
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if the HTTP server supports ``X-Sendfile``, ``use_x_sendfile=True``
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will tell the server to send the given path, which is much more
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efficient than reading it in Python.
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:param path_or_file: The path to the file to send, relative to the
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current working directory if a relative path is given.
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Alternatively, a file-like object opened in binary mode. Make
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sure the file pointer is seeked to the start of the data.
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:param environ: The WSGI environ for the current request.
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:param mimetype: The MIME type to send for the file. If not
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provided, it will try to detect it from the file name.
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:param as_attachment: Indicate to a browser that it should offer to
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save the file instead of displaying it.
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:param download_name: The default name browsers will use when saving
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the file. Defaults to the passed file name.
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:param conditional: Enable conditional and range responses based on
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request headers. Requires passing a file path and ``environ``.
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:param etag: Calculate an ETag for the file, which requires passing
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a file path. Can also be a string to use instead.
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:param last_modified: The last modified time to send for the file,
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in seconds. If not provided, it will try to detect it from the
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file path.
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:param max_age: How long the client should cache the file, in
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seconds. If set, ``Cache-Control`` will be ``public``, otherwise
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it will be ``no-cache`` to prefer conditional caching.
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:param use_x_sendfile: Set the ``X-Sendfile`` header to let the
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server to efficiently send the file. Requires support from the
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HTTP server. Requires passing a file path.
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:param response_class: Build the response using this class. Defaults
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to :class:`~werkzeug.wrappers.Response`.
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:param _root_path: Do not use. For internal use only. Use
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:func:`send_from_directory` to safely send files under a path.
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.. versionchanged:: 2.0.2
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``send_file`` only sets a detected ``Content-Encoding`` if
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``as_attachment`` is disabled.
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.. versionadded:: 2.0
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Adapted from Flask's implementation.
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.. versionchanged:: 2.0
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``download_name`` replaces Flask's ``attachment_filename``
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parameter. If ``as_attachment=False``, it is passed with
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``Content-Disposition: inline`` instead.
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.. versionchanged:: 2.0
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``max_age`` replaces Flask's ``cache_timeout`` parameter.
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``conditional`` is enabled and ``max_age`` is not set by
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default.
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.. versionchanged:: 2.0
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``etag`` replaces Flask's ``add_etags`` parameter. It can be a
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string to use instead of generating one.
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.. versionchanged:: 2.0
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If an encoding is returned when guessing ``mimetype`` from
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``download_name``, set the ``Content-Encoding`` header.
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"""
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if response_class is None:
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from .wrappers import Response
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response_class = Response
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path: str | None = None
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file: t.IO[bytes] | None = None
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size: int | None = None
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mtime: float | None = None
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headers = Headers()
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if isinstance(path_or_file, (os.PathLike, str)) or hasattr(
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path_or_file, "__fspath__"
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):
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path_or_file = t.cast(t.Union[os.PathLike, str], path_or_file)
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# Flask will pass app.root_path, allowing its send_file wrapper
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# to not have to deal with paths.
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if _root_path is not None:
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path = os.path.join(_root_path, path_or_file)
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else:
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path = os.path.abspath(path_or_file)
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stat = os.stat(path)
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size = stat.st_size
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mtime = stat.st_mtime
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else:
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file = path_or_file
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if download_name is None and path is not None:
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download_name = os.path.basename(path)
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if mimetype is None:
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if download_name is None:
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raise TypeError(
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"Unable to detect the MIME type because a file name is"
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" not available. Either set 'download_name', pass a"
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" path instead of a file, or set 'mimetype'."
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)
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mimetype, encoding = mimetypes.guess_type(download_name)
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if mimetype is None:
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mimetype = "application/octet-stream"
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# Don't send encoding for attachments, it causes browsers to
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# save decompress tar.gz files.
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if encoding is not None and not as_attachment:
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headers.set("Content-Encoding", encoding)
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if download_name is not None:
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try:
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download_name.encode("ascii")
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except UnicodeEncodeError:
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simple = unicodedata.normalize("NFKD", download_name)
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simple = simple.encode("ascii", "ignore").decode("ascii")
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# safe = RFC 5987 attr-char
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quoted = quote(download_name, safe="!#$&+-.^_`|~")
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names = {"filename": simple, "filename*": f"UTF-8''{quoted}"}
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else:
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names = {"filename": download_name}
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value = "attachment" if as_attachment else "inline"
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headers.set("Content-Disposition", value, **names)
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elif as_attachment:
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raise TypeError(
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"No name provided for attachment. Either set"
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" 'download_name' or pass a path instead of a file."
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)
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if use_x_sendfile and path is not None:
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headers["X-Sendfile"] = path
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data = None
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else:
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if file is None:
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file = open(path, "rb") # type: ignore
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elif isinstance(file, io.BytesIO):
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size = file.getbuffer().nbytes
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elif isinstance(file, io.TextIOBase):
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raise ValueError("Files must be opened in binary mode or use BytesIO.")
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data = wrap_file(environ, file)
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rv = response_class(
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data, mimetype=mimetype, headers=headers, direct_passthrough=True
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)
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if size is not None:
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rv.content_length = size
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if last_modified is not None:
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rv.last_modified = last_modified # type: ignore
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elif mtime is not None:
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rv.last_modified = mtime # type: ignore
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rv.cache_control.no_cache = True
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# Flask will pass app.get_send_file_max_age, allowing its send_file
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# wrapper to not have to deal with paths.
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if callable(max_age):
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max_age = max_age(path)
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if max_age is not None:
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if max_age > 0:
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rv.cache_control.no_cache = None
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rv.cache_control.public = True
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rv.cache_control.max_age = max_age
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rv.expires = int(time() + max_age) # type: ignore
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|
|
if isinstance(etag, str):
|
|
rv.set_etag(etag)
|
|
elif etag and path is not None:
|
|
check = adler32(path.encode()) & 0xFFFFFFFF
|
|
rv.set_etag(f"{mtime}-{size}-{check}")
|
|
|
|
if conditional:
|
|
try:
|
|
rv = rv.make_conditional(environ, accept_ranges=True, complete_length=size)
|
|
except RequestedRangeNotSatisfiable:
|
|
if file is not None:
|
|
file.close()
|
|
|
|
raise
|
|
|
|
# Some x-sendfile implementations incorrectly ignore the 304
|
|
# status code and send the file anyway.
|
|
if rv.status_code == 304:
|
|
rv.headers.pop("x-sendfile", None)
|
|
|
|
return rv
|
|
|
|
|
|
def send_from_directory(
|
|
directory: os.PathLike | str,
|
|
path: os.PathLike | str,
|
|
environ: WSGIEnvironment,
|
|
**kwargs: t.Any,
|
|
) -> Response:
|
|
"""Send a file from within a directory using :func:`send_file`.
|
|
|
|
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,
|
|
returns a 404 :exc:`~werkzeug.exceptions.NotFound` error.
|
|
|
|
:param directory: The directory that ``path`` must be located under. This *must not*
|
|
be a value provided by the client, otherwise it becomes insecure.
|
|
:param path: The path to the file to send, relative to ``directory``. This is the
|
|
part of the path provided by the client, which is checked for security.
|
|
:param environ: The WSGI environ for the current request.
|
|
:param kwargs: Arguments to pass to :func:`send_file`.
|
|
|
|
.. versionadded:: 2.0
|
|
Adapted from Flask's implementation.
|
|
"""
|
|
path = safe_join(os.fspath(directory), os.fspath(path))
|
|
|
|
if path is None:
|
|
raise NotFound()
|
|
|
|
# Flask will pass app.root_path, allowing its send_from_directory
|
|
# wrapper to not have to deal with paths.
|
|
if "_root_path" in kwargs:
|
|
path = os.path.join(kwargs["_root_path"], path)
|
|
|
|
if not os.path.isfile(path):
|
|
raise NotFound()
|
|
|
|
return send_file(path, environ, **kwargs)
|
|
|
|
|
|
def import_string(import_name: str, silent: bool = False) -> t.Any:
|
|
"""Imports an object based on a string. This is useful if you want to
|
|
use import paths as endpoints or something similar. An import path can
|
|
be specified either in dotted notation (``xml.sax.saxutils.escape``)
|
|
or with a colon as object delimiter (``xml.sax.saxutils:escape``).
|
|
|
|
If `silent` is True the return value will be `None` if the import fails.
|
|
|
|
:param import_name: the dotted name for the object to import.
|
|
:param silent: if set to `True` import errors are ignored and
|
|
`None` is returned instead.
|
|
:return: imported object
|
|
"""
|
|
import_name = import_name.replace(":", ".")
|
|
try:
|
|
try:
|
|
__import__(import_name)
|
|
except ImportError:
|
|
if "." not in import_name:
|
|
raise
|
|
else:
|
|
return sys.modules[import_name]
|
|
|
|
module_name, obj_name = import_name.rsplit(".", 1)
|
|
module = __import__(module_name, globals(), locals(), [obj_name])
|
|
try:
|
|
return getattr(module, obj_name)
|
|
except AttributeError as e:
|
|
raise ImportError(e) from None
|
|
|
|
except ImportError as e:
|
|
if not silent:
|
|
raise ImportStringError(import_name, e).with_traceback(
|
|
sys.exc_info()[2]
|
|
) from None
|
|
|
|
return None
|
|
|
|
|
|
def find_modules(
|
|
import_path: str, include_packages: bool = False, recursive: bool = False
|
|
) -> t.Iterator[str]:
|
|
"""Finds all the modules below a package. This can be useful to
|
|
automatically import all views / controllers so that their metaclasses /
|
|
function decorators have a chance to register themselves on the
|
|
application.
|
|
|
|
Packages are not returned unless `include_packages` is `True`. This can
|
|
also recursively list modules but in that case it will import all the
|
|
packages to get the correct load path of that module.
|
|
|
|
:param import_path: the dotted name for the package to find child modules.
|
|
:param include_packages: set to `True` if packages should be returned, too.
|
|
:param recursive: set to `True` if recursion should happen.
|
|
:return: generator
|
|
"""
|
|
module = import_string(import_path)
|
|
path = getattr(module, "__path__", None)
|
|
if path is None:
|
|
raise ValueError(f"{import_path!r} is not a package")
|
|
basename = f"{module.__name__}."
|
|
for _importer, modname, ispkg in pkgutil.iter_modules(path):
|
|
modname = basename + modname
|
|
if ispkg:
|
|
if include_packages:
|
|
yield modname
|
|
if recursive:
|
|
yield from find_modules(modname, include_packages, True)
|
|
else:
|
|
yield modname
|
|
|
|
|
|
class ImportStringError(ImportError):
|
|
"""Provides information about a failed :func:`import_string` attempt."""
|
|
|
|
#: String in dotted notation that failed to be imported.
|
|
import_name: str
|
|
#: Wrapped exception.
|
|
exception: BaseException
|
|
|
|
def __init__(self, import_name: str, exception: BaseException) -> None:
|
|
self.import_name = import_name
|
|
self.exception = exception
|
|
msg = import_name
|
|
name = ""
|
|
tracked = []
|
|
for part in import_name.replace(":", ".").split("."):
|
|
name = f"{name}.{part}" if name else part
|
|
imported = import_string(name, silent=True)
|
|
if imported:
|
|
tracked.append((name, getattr(imported, "__file__", None)))
|
|
else:
|
|
track = [f"- {n!r} found in {i!r}." for n, i in tracked]
|
|
track.append(f"- {name!r} not found.")
|
|
track_str = "\n".join(track)
|
|
msg = (
|
|
f"import_string() failed for {import_name!r}. Possible reasons"
|
|
f" are:\n\n"
|
|
"- missing __init__.py in a package;\n"
|
|
"- package or module path not included in sys.path;\n"
|
|
"- duplicated package or module name taking precedence in"
|
|
" sys.path;\n"
|
|
"- missing module, class, function or variable;\n\n"
|
|
f"Debugged import:\n\n{track_str}\n\n"
|
|
f"Original exception:\n\n{type(exception).__name__}: {exception}"
|
|
)
|
|
break
|
|
|
|
super().__init__(msg)
|
|
|
|
def __repr__(self) -> str:
|
|
return f"<{type(self).__name__}({self.import_name!r}, {self.exception!r})>"
|