http.cookies — HTTP state management¶Source code: Lib/http/cookies.py
The 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, string.ascii_letters, string.digits and
!#$%&'*+-.^_`|~: denote the set of valid characters allowed by this module
in a cookie name (as key).
Changed in version 3.3: Allowed ‘:’ as a valid cookie name character.
Changed in version 3.15: Allowed ‘"’ as a valid cookie value character.
Note
On encountering an invalid cookie, CookieError is raised, so if your
cookie data comes from a browser you should always prepare for invalid data
and catch CookieError on parsing.
Exception failing because of RFC 2109 invalidity: incorrect attributes, incorrect Set-Cookie header, etc.
This class is a dictionary-like object whose keys are strings and whose values
are Morsel instances. Note that upon setting a key to a value, the
value is first converted to a Morsel containing the key and the value.
If input is given, it is passed to the load() method.
This class derives from BaseCookie and overrides value_decode()
and value_encode(). SimpleCookie supports
strings as cookie values. When setting the value, SimpleCookie
calls the builtin str() to convert
the value to a string. Values received from HTTP are kept as strings.
See also
http.cookiejarHTTP cookie handling for web clients. The http.cookiejar and
http.cookies modules do not depend on each other.
This is the state management specification implemented by this module.
Return a tuple (real_value, coded_value) from a string representation.
real_value can be any type. This method does no decoding in
BaseCookie — it exists so it can be overridden.
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 BaseCookie — it exists so it can
be overridden.
In general, it should be the case that value_encode() and
value_decode() are inverses on the range of value_decode.
Return a string representation suitable to be sent as HTTP headers. attrs and
header are sent to each Morsel’s output() method. sep is used
to join the headers together, and is by default the combination '\r\n'
(CRLF).
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:
The attribute 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 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 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 ''.
Changed in version 3.7: Attributes key, value and
coded_value are read-only. Use set() for
setting them.
Changed in version 3.8: Added support for the samesite attribute.
Changed in version 3.14: Added support for the partitioned attribute.
The value of the cookie.
The encoded value of the cookie — this is what should be sent.
The name of the cookie.
Set the key, value and coded_value attributes.
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:".
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 output().
Return a string representing the Morsel, without any surrounding HTTP or JavaScript.
The meaning for attrs is the same as in output().
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.
Changed in version 3.5: an error is raised for invalid keys.
Return a shallow copy of the Morsel object.
Changed in version 3.5: return a Morsel object instead of a dict.
Raise an error if key is not a valid RFC 2109 attribute, otherwise
behave the same as dict.setdefault().
The following example demonstrates how to use the 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=;";')
>>> 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