http.cookies
— HTTP状态管理¶
源代码: Lib/http/cookies.py
http.cookies
模块定义的类将 cookie 的概念抽象了出来,这是一种 HTTP 状态的管理机制。它既支持简单的纯字符串形式的 cookie,也为任何可序列化数据类型的 cookie 提供抽象。
以前,该模块严格套用 RFC 2109 和 RFC 2068 规范中描述的解析规则。后来人们发现,MSIE 3.0 并不遵循这些规范中的字符规则,而且目前许多浏览器和服务器在处理 cookie 时也放宽了解析规则。 因此,这里用到的解析规则没有那么严格。
字符集 string.ascii_letters
、 string.digits
和 !#$%&'*+-.^_`|~:
给出了本模块允许出现在 cookie 名称中的有效字符集(如 key
)。
在 3.3 版更改: “:”字符可用于有效的 cookie 名称。
备注
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 http.cookies.CookieError¶
Exception failing because of RFC 2109 invalidity: incorrect attributes, incorrect Set-Cookie header, etc.
- class http.cookies.BaseCookie([input])¶
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.
- class http.cookies.SimpleCookie([input])¶
This class derives from
BaseCookie
and overridesvalue_decode()
andvalue_encode()
. SimpleCookie supports strings as cookie values. When setting the value, SimpleCookie calls the builtinstr()
to convert the value to a string. Values received from HTTP are kept as strings.
参见
- Module
http.cookiejar
HTTP cookie handling for web clients. The
http.cookiejar
andhttp.cookies
modules do not depend on each other.- RFC 2109 - HTTP状态管理机制
This is the state management specification implemented by this module.
Cookie 对象¶
- 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 inBaseCookie
— it exists so it can be overridden.
- BaseCookie.value_encode(val)¶
Return a tuple
(real_value, coded_value)
. val can be any type, butcoded_value
will always be converted to a string. This method does no encoding inBaseCookie
— 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.
- 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
Morsel
’soutput()
method. sep is used to join the headers together, and is by default the combination'\r\n'
(CRLF).
Morsel 对象¶
- class http.cookies.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
expires
path
comment
domain
max-age
secure
version
httponly
samesite
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
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 keys are case-insensitive and their default value is
''
.在 3.7 版更改: Attributes
key
,value
andcoded_value
are read-only. Useset()
for setting them.在 3.8 版更改: Added support for the
samesite
attribute.
- Morsel.value¶
Cookie的值。
- Morsel.coded_value¶
The encoded value of the cookie — this is what should be sent.
- Morsel.key¶
The name of the cookie.
- Morsel.set(key, value, coded_value)¶
Set the key, value and coded_value attributes.
- 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:"
.
- 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
output()
.
- 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
output()
.
- 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.
在 3.5 版更改: an error is raised for invalid keys.
- Morsel.copy(value)¶
Return a shallow copy of the Morsel object.
在 3.5 版更改: return a Morsel object instead of a dict.
- Morsel.setdefault(key, value=None)¶
Raise an error if key is not a valid RFC 2109 attribute, otherwise behave the same as
dict.setdefault()
.
示例¶
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