Doc/library/http.cookies.rst
!http.cookies --- HTTP state management.. module:: http.cookies :synopsis: Support for HTTP state management (cookies).
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.
.. versionchanged:: 3.15
Allowed '"' as a valid cookie value 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.
.. class:: BaseCookie([input])
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.
.. class:: SimpleCookie([input])
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.
.. _cookie-objects:
.. 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
.. _morsel-objects:
.. class:: Morsel
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 controls when the browser sends the cookie with
cross-site requests. This helps to mitigate CSRF attacks. Valid values are
"Strict" (only sent with same-site requests), "Lax" (sent with same-site
requests and top-level navigations), and "None" (sent with same-site and
cross-site requests). When using "None", the "secure" attribute must also
be set, as required by modern browsers.
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.
.. _CHIPS (Cookies Having Independent Partitioned State): https://github.com/privacycg/CHIPS/blob/main/README.md
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.
.. _cookie-example:
The following example demonstrates how to use the :mod:!http.cookies module.
.. doctest:: :options: +NORMALIZE_WHITESPACE
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=;";') print(C) Set-Cookie: keebler="E=everybody; L="Loves"; fudge=;" 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 import json C = cookies.SimpleCookie() C.load(f'cookies=7; mixins="{json.dumps({"chips": "dark chocolate"})}"; state=gooey') print(C) Set-Cookie: cookies=7 Set-Cookie: mixins="{"chips": "dark chocolate"}" Set-Cookie: state=gooey