http.cookies --- HTTP状态管理

源代码: Lib/http/cookies.py

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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。

注解

当遇到无效 cookie 时会触发 CookieError，所以若 cookie 数据来自浏览器，一定要做好应对无效数据的准备，并在解析时捕获 CookieError。

exception http.cookies.CookieError

出现异常的原因，可能是不符合 RFC 2109 ：属性不正确、Set-Cookie 头部信息不正确等等。

class http.cookies.BaseCookie([input])

类似字典的对象，字典键为字符串，字典值是 Morsel 实例。请注意，在将键值关联时，首先会把值转换为包含键和值的 Morsel 对象。

若给出 input ，将会传给 load() 方法。

class http.cookies.SimpleCookie([input])

该类派生于 BaseCookie，并覆盖了 value_decode() 和 value_encode() 方法。SimpleCookie 允许用字符串作为 cookie 值。在设置值时，SimpleCookie 将调用内置的 str() 将其转换为字符串。从 HTTP 接收到的值将作为字符串保存。

参见

http.cookiejar 模块

处理网络 客户端 的 HTTP cookie。 http.cookiejar 和 http.cookies 模块相互没有依赖关系。

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 in BaseCookie --- it exists so it can be overridden.

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 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.

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's output() method. sep is used to join the headers together, and is by default the combination '\r\n' (CRLF).

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 output().

BaseCookie.load(rawdata)

If rawdata is a string, parse it as an HTTP_COOKIE and add the values found there as Morsels. If it is a dictionary, it is equivalent to:

for k, v in rawdata.items():
    cookie[k] = v

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 3.5 版更改: __eq__() now takes key and value into account.

在 3.7 版更改: Attributes key, value and coded_value are read-only. Use set() 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.isReservedKey(K)

Whether K is a member of the set of keys of a Morsel.

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