21.23. 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 doesn’t follow the character rules outlined in those specs and also many current day browsers and servers have relaxed parsing rules when comes to Cookie handling. As a result, the parsing rules used are a bit less strict.
The character set, string.ascii_letters
, string.digits
and
!#$%&'*+-.^_`|~:
denote the set of valid characters allowed by this module
in Cookie name (as key
).
Distinto en la versión 3.3: Allowed “:” as a valid Cookie name character.
Nota
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 aMorsel
containing the key and the value.If input is given, it is passed to the
load()
method.
This class derives from
BaseCookie
and overridesvalue_decode()
andvalue_encode()
to be the identity andstr()
respectively.
Ver también
- Module
http.cookiejar
- HTTP cookie handling for web clients. The
http.cookiejar
andhttp.cookies
modules do not depend on each other. - RFC 2109 - HTTP State Management Mechanism
- This is the state management specification implemented by this module.
21.23.1. Cookie Objects¶
Return a decoded value from a string representation. Return value can be any type. This method does nothing in
BaseCookie
— it exists so it can be overridden.
Return an encoded value. val can be any type, but return value must be a string. This method does nothing in
BaseCookie
— it exists so it can be overridden.In general, it should be the case that
value_encode()
andvalue_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
’soutput()
method. sep is used to join the headers together, and is by default the combination'\r\n'
(CRLF).
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
output()
.
If rawdata is a string, parse it as an
HTTP_COOKIE
and add the values found there asMorsel
s. If it is a dictionary, it is equivalent to:for k, v in rawdata.items(): cookie[k] = v
21.23.2. Morsel Objects¶
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
expires
path
comment
domain
max-age
secure
version
httponly
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 keys are case-insensitive and their default value is
''
.
The value of the cookie.
Obsoleto desde la versión 3.5: assigning to
value
; useset()
instead.
The encoded value of the cookie — this is what should be sent.
Obsoleto desde la versión 3.5: assigning to
coded_value
; useset()
instead.
The name of the cookie.
Obsoleto desde la versión 3.5: assigning to
key
; useset()
instead.
Set the key, value and coded_value attributes.
Obsoleto desde la versión 3.5: The undocumented LegalChars parameter is ignored and will be removed in a future version.
Whether K is a member of the set of keys of a
Morsel
.
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.
Distinto en la versión 3.5: an error is raised for invalid keys.
Return a shallow copy of the Morsel object.
Distinto en la versión 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()
.
21.23.3. Example¶
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=\\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