:mod:`!http.cookies` --- HTTP state management
.. module:: http.cookies :synopsis: Support for HTTP state management (cookies).
.. moduleauthor:: Timothy O'Malley <[email protected]>
.. sectionauthor:: Moshe Zadka <[email protected]>
Source code: :source:`Lib/http/cookies.py`
The :mod:`http.cookies` module defines classes for abstracting the concept of cookies, an HTTP state management mechanism. It supports both simple string-only cookies, and provides an abstraction for having any serializable data-type as cookie value.
The module formerly strictly applied the parsing rules described in the RFC 2109 and RFC 2068 specifications. It has since been discovered that MSIE 3.0x didn't follow the character rules outlined in those specs; many current-day browsers and servers have also relaxed parsing rules when it comes to cookie handling. As a result, this module now uses parsing rules that are a bit less strict than they once were.
The character set, :data:`string.ascii_letters`, :data:`string.digits` and
!#$%&'*+-.^_`|~: denote the set of valid characters allowed by this module
in a cookie name (as :attr:`~Morsel.key`).
.. versionchanged:: 3.3 Allowed ':' as a valid cookie name character.
Note
On encountering an invalid cookie, :exc:`CookieError` is raised, so if your cookie data comes from a browser you should always prepare for invalid data and catch :exc:`CookieError` on parsing.
.. exception:: CookieError Exception failing because of :rfc:`2109` invalidity: incorrect attributes, incorrect :mailheader:`Set-Cookie` header, etc.
This class is a dictionary-like object whose keys are strings and whose values are :class:`Morsel` instances. Note that upon setting a key to a value, the value is first converted to a :class:`Morsel` containing the key and the value.
If input is given, it is passed to the :meth:`load` method.
This class derives from :class:`BaseCookie` and overrides :meth:`~BaseCookie.value_decode` and :meth:`~BaseCookie.value_encode`. :class:`!SimpleCookie` supports strings as cookie values. When setting the value, :class:`!SimpleCookie` calls the builtin :func:`str` to convert the value to a string. Values received from HTTP are kept as strings.
.. seealso::
Module :mod:`http.cookiejar`
HTTP cookie handling for web *clients*. The :mod:`http.cookiejar` and
:mod:`http.cookies` modules do not depend on each other.
:rfc:`2109` - HTTP State Management Mechanism
This is the state management specification implemented by this module.
.. method:: BaseCookie.value_decode(val) Return a tuple ``(real_value, coded_value)`` from a string representation. ``real_value`` can be any type. This method does no decoding in :class:`BaseCookie` --- it exists so it can be overridden.
.. method:: BaseCookie.value_encode(val) Return a tuple ``(real_value, coded_value)``. *val* can be any type, but ``coded_value`` will always be converted to a string. This method does no encoding in :class:`BaseCookie` --- it exists so it can be overridden. In general, it should be the case that :meth:`value_encode` and :meth:`value_decode` are inverses on the range of *value_decode*.
.. method:: BaseCookie.output(attrs=None, header='Set-Cookie:', sep='\r\n') Return a string representation suitable to be sent as HTTP headers. *attrs* and *header* are sent to each :class:`Morsel`'s :meth:`~Morsel.output` method. *sep* is used to join the headers together, and is by default the combination ``'\r\n'`` (CRLF).
.. method:: BaseCookie.js_output(attrs=None) Return an embeddable JavaScript snippet, which, if run on a browser which supports JavaScript, will act the same as if the HTTP headers was sent. The meaning for *attrs* is the same as in :meth:`output`.
.. method:: BaseCookie.load(rawdata)
If *rawdata* is a string, parse it as an ``HTTP_COOKIE`` and add the values
found there as :class:`Morsel`\ s. If it is a dictionary, it is equivalent to::
for k, v in rawdata.items():
cookie[k] = v
Abstract a key/value pair, which has some RFC 2109 attributes.
Morsels are dictionary-like objects, whose set of keys is constant --- the valid RFC 2109 attributes, which are:
.. attribute:: expires
path
comment
domain
max-age
secure
version
httponly
samesite
partitioned
The attribute :attr:`httponly` specifies that the cookie is only transferred in HTTP requests, and is not accessible through JavaScript. This is intended to mitigate some forms of cross-site scripting.
The attribute :attr:`samesite` specifies that the browser is not allowed to send the cookie along with cross-site requests. This helps to mitigate CSRF attacks. Valid values for this attribute are "Strict" and "Lax".
The attribute :attr:`partitioned` indicates to user agents that these
cross-site cookies should only be available in the same top-level context
that the cookie was first set in. For this to be accepted by the user agent,
you must also set Secure.
In addition, it is recommended to use the __Host prefix when setting
partitioned cookies to make them bound to the hostname and not the
registrable domain. Read
CHIPS (Cookies Having Independent Partitioned State)
for full details and examples.
The keys are case-insensitive and their default value is ''.
.. versionchanged:: 3.5 :meth:`!__eq__` now takes :attr:`~Morsel.key` and :attr:`~Morsel.value` into account.
.. versionchanged:: 3.7 Attributes :attr:`~Morsel.key`, :attr:`~Morsel.value` and :attr:`~Morsel.coded_value` are read-only. Use :meth:`~Morsel.set` for setting them.
.. versionchanged:: 3.8 Added support for the :attr:`samesite` attribute.
.. versionchanged:: 3.14 Added support for the :attr:`partitioned` attribute.
.. attribute:: Morsel.value The value of the cookie.
.. attribute:: Morsel.coded_value The encoded value of the cookie --- this is what should be sent.
.. attribute:: Morsel.key The name of the cookie.
.. method:: Morsel.set(key, value, coded_value) Set the *key*, *value* and *coded_value* attributes.
.. method:: Morsel.isReservedKey(K) Whether *K* is a member of the set of keys of a :class:`Morsel`.
.. method:: Morsel.output(attrs=None, header='Set-Cookie:') Return a string representation of the Morsel, suitable to be sent as an HTTP header. By default, all the attributes are included, unless *attrs* is given, in which case it should be a list of attributes to use. *header* is by default ``"Set-Cookie:"``.
.. method:: Morsel.js_output(attrs=None) Return an embeddable JavaScript snippet, which, if run on a browser which supports JavaScript, will act the same as if the HTTP header was sent. The meaning for *attrs* is the same as in :meth:`output`.
.. method:: Morsel.OutputString(attrs=None) Return a string representing the Morsel, without any surrounding HTTP or JavaScript. The meaning for *attrs* is the same as in :meth:`output`.
.. method:: Morsel.update(values)
Update the values in the Morsel dictionary with the values in the dictionary
*values*. Raise an error if any of the keys in the *values* dict is not a
valid :rfc:`2109` attribute.
.. versionchanged:: 3.5
an error is raised for invalid keys.
.. method:: Morsel.copy(value)
Return a shallow copy of the Morsel object.
.. versionchanged:: 3.5
return a Morsel object instead of a dict.
.. method:: Morsel.setdefault(key, value=None) Raise an error if key is not a valid :rfc:`2109` attribute, otherwise behave the same as :meth:`dict.setdefault`.
The following example demonstrates how to use the :mod:`http.cookies` module.
>>> from http import cookies
>>> C = cookies.SimpleCookie()
>>> C["fig"] = "newton"
>>> C["sugar"] = "wafer"
>>> print(C) # generate HTTP headers
Set-Cookie: fig=newton
Set-Cookie: sugar=wafer
>>> print(C.output()) # same thing
Set-Cookie: fig=newton
Set-Cookie: sugar=wafer
>>> C = cookies.SimpleCookie()
>>> C["rocky"] = "road"
>>> C["rocky"]["path"] = "/cookie"
>>> print(C.output(header="Cookie:"))
Cookie: rocky=road; Path=/cookie
>>> print(C.output(attrs=[], header="Cookie:"))
Cookie: rocky=road
>>> C = cookies.SimpleCookie()
>>> C.load("chips=ahoy; vienna=finger") # load from a string (HTTP header)
>>> print(C)
Set-Cookie: chips=ahoy
Set-Cookie: vienna=finger
>>> C = cookies.SimpleCookie()
>>> C.load('keebler="E=everybody; L=\\"Loves\\"; fudge=\\012;";')
>>> print(C)
Set-Cookie: keebler="E=everybody; L=\"Loves\"; fudge=\012;"
>>> C = cookies.SimpleCookie()
>>> C["oreo"] = "doublestuff"
>>> C["oreo"]["path"] = "/"
>>> print(C)
Set-Cookie: oreo=doublestuff; Path=/
>>> C = cookies.SimpleCookie()
>>> C["twix"] = "none for you"
>>> C["twix"].value
'none for you'
>>> C = cookies.SimpleCookie()
>>> C["number"] = 7 # equivalent to C["number"] = str(7)
>>> C["string"] = "seven"
>>> C["number"].value
'7'
>>> C["string"].value
'seven'
>>> print(C)
Set-Cookie: number=7
Set-Cookie: string=seven