http.cookiejar
--- HTTP 客戶端的 Cookie 處理¶
Thehttp.cookiejar
module defines classes for automatic handling of HTTPcookies. It is useful for accessing web sites that require small pieces of data--cookies -- to be set on the client machine by an HTTP response from aweb server, and then returned to the server in later HTTP requests.
Both the regular Netscape cookie protocol and the protocol defined byRFC 2965 are handled. RFC 2965 handling is switched off by default.RFC 2109 cookies are parsed as Netscape cookies and subsequently treatedeither as Netscape or RFC 2965 cookies according to the 'policy' in effect.Note that the great majority of cookies on the internet are Netscape cookies.http.cookiejar
attempts to follow the de-facto Netscape cookie protocol (whichdiffers substantially from that set out in the original Netscape specification),including taking note of themax-age
andport
cookie-attributesintroduced with RFC 2965.
備註
The various named parameters found inSet-Cookie andSet-Cookie2 headers (eg.domain
andexpires
) areconventionally referred to asattributes. To distinguish them fromPython attributes, the documentation for this module uses the termcookie-attribute instead.
The module defines the following exception:
- exceptionhttp.cookiejar.LoadError¶
Instances of
FileCookieJar
raise this exception on failure to loadcookies from a file.LoadError
is a subclass ofOSError
.
提供了以下類別:
- classhttp.cookiejar.CookieJar(policy=None)¶
policy is an object implementing the
CookiePolicy
interface.The
CookieJar
class stores HTTP cookies. It extracts cookies from HTTPrequests, and returns them in HTTP responses.CookieJar
instancesautomatically expire contained cookies when necessary. Subclasses are alsoresponsible for storing and retrieving cookies from a file or database.
- classhttp.cookiejar.FileCookieJar(filename=None,delayload=None,policy=None)¶
policy is an object implementing the
CookiePolicy
interface. For theother arguments, see the documentation for the corresponding attributes.A
CookieJar
which can load cookies from, and perhaps save cookies to, afile on disk. Cookies areNOT loaded from the named file until either theload()
orrevert()
method is called. Subclasses of this class aredocumented in sectionFileCookieJar subclasses and co-operation with web browsers.This should not be initialized directly – use its subclasses below instead.
在 3.8 版的變更:The filename parameter supports apath-like object.
- classhttp.cookiejar.CookiePolicy¶
This class is responsible for deciding whether each cookie should be acceptedfrom / returned to the server.
- classhttp.cookiejar.DefaultCookiePolicy(blocked_domains=None,allowed_domains=None,netscape=True,rfc2965=False,rfc2109_as_netscape=None,hide_cookie2=False,strict_domain=False,strict_rfc2965_unverifiable=True,strict_ns_unverifiable=False,strict_ns_domain=DefaultCookiePolicy.DomainLiberal,strict_ns_set_initial_dollar=False,strict_ns_set_path=False,secure_protocols=('https','wss'))¶
Constructor arguments should be passed as keyword arguments only.blocked_domains is a sequence of domain names that we never accept cookiesfrom, nor return cookies to.allowed_domains if not
None
, this is asequence of the only domains for which we accept and return cookies.secure_protocols is a sequence of protocols for which secure cookies can beadded to. By defaulthttps andwss (secure websocket) are consideredsecure protocols. For all other arguments, see the documentation forCookiePolicy
andDefaultCookiePolicy
objects.DefaultCookiePolicy
implements the standard accept / reject rules forNetscape andRFC 2965 cookies. By default,RFC 2109 cookies (ie. cookiesreceived in aSet-Cookie header with a version cookie-attribute of1) are treated according to the RFC 2965 rules. However, if RFC 2965 handlingis turned off orrfc2109_as_netscape
isTrue
, RFC 2109 cookies are'downgraded' by theCookieJar
instance to Netscape cookies, bysetting theversion
attribute of theCookie
instance to 0.DefaultCookiePolicy
also provides some parameters to allow somefine-tuning of policy.
- classhttp.cookiejar.Cookie¶
This class represents Netscape,RFC 2109 andRFC 2965 cookies. It is notexpected that users of
http.cookiejar
construct their ownCookie
instances. Instead, if necessary, callmake_cookies()
on aCookieJar
instance.
也參考
urllib.request
模組URL opening with automatic cookie handling.
http.cookies
模組HTTP cookie classes, principally useful for server-side code. The
http.cookiejar
andhttp.cookies
modules do not depend on eachother.- https://curl.se/rfc/cookie_spec.html
The specification of the original Netscape cookie protocol. Though this isstill the dominant protocol, the 'Netscape cookie protocol' implemented by allthe major browsers (and
http.cookiejar
) only bears a passing resemblance tothe one sketched out incookie_spec.html
.- RFC 2109 - HTTP State Management Mechanism
Obsoleted byRFC 2965. UsesSet-Cookie with version=1.
- RFC 2965 - HTTP State Management Mechanism
The Netscape protocol with the bugs fixed. UsesSet-Cookie2 inplace ofSet-Cookie. Not widely used.
- https://kristol.org/cookie/errata.html
Unfinished errata toRFC 2965.
RFC 2964 - Use of HTTP State Management
CookieJar 與 FileCookieJar 物件¶
CookieJar
objects support theiterator protocol for iterating overcontainedCookie
objects.
CookieJar
擁有以下方法:
- CookieJar.add_cookie_header(request)¶
將正確的Cookie 標頭加入request。
If policy allows (ie. the
rfc2965
andhide_cookie2
attributes oftheCookieJar
'sCookiePolicy
instance are true and falserespectively), theCookie2 header is also added when appropriate.Therequest object (usually a
urllib.request.Request
instance)must support the methodsget_full_url()
,has_header()
,get_header()
,header_items()
,add_unredirected_header()
and the attributeshost
,type
,unverifiable
andorigin_req_host
as documented byurllib.request
.在 3.3 版的變更:request object needs
origin_req_host
attribute. Dependency on adeprecated methodget_origin_req_host()
has been removed.
- CookieJar.extract_cookies(response,request)¶
Extract cookies from HTTPresponse and store them in the
CookieJar
,where allowed by policy.The
CookieJar
will look for allowableSet-Cookie andSet-Cookie2 headers in theresponse argument, and store cookiesas appropriate (subject to theCookiePolicy.set_ok()
method's approval).Theresponse object (usually the result of a call to
urllib.request.urlopen()
, or similar) should support aninfo()
method, which returns anemail.message.Message
instance.Therequest object (usually a
urllib.request.Request
instance)must support the methodget_full_url()
and the attributeshost
,unverifiable
andorigin_req_host
,as documented byurllib.request
. The request is used to setdefault values for cookie-attributes as well as for checking that thecookie is allowed to be set.在 3.3 版的變更:request object needs
origin_req_host
attribute. Dependency on adeprecated methodget_origin_req_host()
has been removed.
- CookieJar.set_policy(policy)¶
Set the
CookiePolicy
instance to be used.
- CookieJar.make_cookies(response,request)¶
Return sequence of
Cookie
objects extracted fromresponse object.See the documentation for
extract_cookies()
for the interfaces required oftheresponse andrequest arguments.
- CookieJar.set_cookie(cookie)¶
Set a
Cookie
, without checking with policy to see whether or not itshould be set.
- CookieJar.clear([domain[,path[,name]]])¶
清除一些 cookies。
If invoked without arguments, clear all cookies. If given a single argument,only cookies belonging to thatdomain will be removed. If given two arguments,cookies belonging to the specifieddomain and URLpath are removed. Ifgiven three arguments, then the cookie with the specifieddomain,path andname is removed.
如果沒有符合的 cookie 存在,則引發
KeyError
。
- CookieJar.clear_session_cookies()¶
Discard all session cookies.
Discards all contained cookies that have a true
discard
attribute(usually because they had either nomax-age
orexpires
cookie-attribute,or an explicitdiscard
cookie-attribute). For interactive browsers, the endof a session usually corresponds to closing the browser window.Note that the
save()
method won't save session cookies anyway, unless youask otherwise by passing a trueignore_discard argument.
FileCookieJar
implements the following additional methods:
- FileCookieJar.save(filename=None,ignore_discard=False,ignore_expires=False)¶
將 cookies 儲存到檔案中。
This base class raises
NotImplementedError
. Subclasses may leave thismethod unimplemented.filename is the name of file in which to save cookies. Iffilename is notspecified,
self.filename
is used (whose default is the value passed tothe constructor, if any); ifself.filename
isNone
,ValueError
is raised.ignore_discard: save even cookies set to be discarded.ignore_expires: saveeven cookies that have expired
The file is overwritten if it already exists, thus wiping all the cookies itcontains. Saved cookies can be restored later using the
load()
orrevert()
methods.
- FileCookieJar.load(filename=None,ignore_discard=False,ignore_expires=False)¶
從檔案中載入 cookies。
舊的 cookies 會被保留,除非被新載入的 cookies 覆蓋。
引數與
save()
相同。The named file must be in the format understood by the class, or
LoadError
will be raised. Also,OSError
may be raised, forexample if the file does not exist.
- FileCookieJar.revert(filename=None,ignore_discard=False,ignore_expires=False)¶
Clear all cookies and reload cookies from a saved file.
revert()
can raise the same exceptions asload()
. If there is afailure, the object's state will not be altered.
FileCookieJar
實例擁有以下公開屬性:
- FileCookieJar.filename¶
Filename of default file in which to keep cookies. This attribute may beassigned to.
- FileCookieJar.delayload¶
If true, load cookies lazily from disk. This attribute should not be assignedto. This is only a hint, since this only affects performance, not behaviour(unless the cookies on disk are changing). A
CookieJar
object mayignore it. None of theFileCookieJar
classes included in the standardlibrary lazily loads cookies.
FileCookieJar subclasses and co-operation with web browsers¶
The followingCookieJar
subclasses are provided for reading andwriting.
- classhttp.cookiejar.MozillaCookieJar(filename=None,delayload=None,policy=None)¶
A
FileCookieJar
that can load from and save cookies to disk in theMozillacookies.txt
file format (which is also used by curl and the Lynxand Netscape browsers).備註
This loses information aboutRFC 2965 cookies, and also about newer ornon-standard cookie-attributes such as
port
.警告
Back up your cookies before saving if you have cookies whose loss / corruptionwould be inconvenient (there are some subtleties which may lead to slightchanges in the file over a load / save round-trip).
Also note that cookies saved while Mozilla is running will get clobbered byMozilla.
- classhttp.cookiejar.LWPCookieJar(filename=None,delayload=None,policy=None)¶
A
FileCookieJar
that can load from and save cookies to disk in formatcompatible with the libwww-perl library'sSet-Cookie3
file format. This isconvenient if you want to store cookies in a human-readable file.在 3.8 版的變更:The filename parameter supports apath-like object.
CookiePolicy 物件¶
Objects implementing theCookiePolicy
interface have the followingmethods:
- CookiePolicy.set_ok(cookie,request)¶
Return boolean value indicating whether cookie should be accepted from server.
cookie is a
Cookie
instance.request is an objectimplementing the interface defined by the documentation forCookieJar.extract_cookies()
.
- CookiePolicy.return_ok(cookie,request)¶
Return boolean value indicating whether cookie should be returned to server.
cookie is a
Cookie
instance.request is an objectimplementing the interface defined by the documentation forCookieJar.add_cookie_header()
.
- CookiePolicy.domain_return_ok(domain,request)¶
Return
False
if cookies should not be returned, given cookie domain.This method is an optimization. It removes the need for checking every cookiewith a particular domain (which might involve reading many files). Returningtrue from
domain_return_ok()
andpath_return_ok()
leaves all thework toreturn_ok()
.If
domain_return_ok()
returns true for the cookie domain,path_return_ok()
is called for the cookie path. Otherwise,path_return_ok()
andreturn_ok()
are never called for that cookiedomain. Ifpath_return_ok()
returns true,return_ok()
is calledwith theCookie
object itself for a full check. Otherwise,return_ok()
is never called for that cookie path.Note that
domain_return_ok()
is called for everycookie domain, not justfor therequest domain. For example, the function might be called with both".example.com"
and"www.example.com"
if the request domain is"www.example.com"
. The same goes forpath_return_ok()
.Therequest argument is as documented for
return_ok()
.
- CookiePolicy.path_return_ok(path,request)¶
Return
False
if cookies should not be returned, given cookie path.關於
domain_return_ok()
請見文件。
In addition to implementing the methods above, implementations of theCookiePolicy
interface must also supply the following attributes,indicating which protocols should be used, and how. All of these attributes maybe assigned to.
- CookiePolicy.netscape¶
實作 Netscape 協定。
- CookiePolicy.hide_cookie2¶
Don't addCookie2 header to requests (the presence of this headerindicates to the server that we understandRFC 2965 cookies).
The most useful way to define aCookiePolicy
class is by subclassingfromDefaultCookiePolicy
and overriding some or all of the methodsabove.CookiePolicy
itself may be used as a 'null policy' to allowsetting and receiving any and all cookies (this is unlikely to be useful).
DefaultCookiePolicy 物件¶
Implements the standard rules for accepting and returning cookies.
BothRFC 2965 and Netscape cookies are covered. RFC 2965 handling is switchedoff by default.
The easiest way to provide your own policy is to override this class and callits methods in your overridden implementations before adding your own additionalchecks:
importhttp.cookiejarclassMyCookiePolicy(http.cookiejar.DefaultCookiePolicy):defset_ok(self,cookie,request):ifnothttp.cookiejar.DefaultCookiePolicy.set_ok(self,cookie,request):returnFalseifi_dont_want_to_store_this_cookie(cookie):returnFalsereturnTrue
In addition to the features required to implement theCookiePolicy
interface, this class allows you to block and allow domains from setting andreceiving cookies. There are also some strictness switches that allow you totighten up the rather loose Netscape protocol rules a little bit (at the cost ofblocking some benign cookies).
A domain blocklist and allowlist is provided (both off by default). Only domainsnot in the blocklist and present in the allowlist (if the allowlist is active)participate in cookie setting and returning. Use theblocked_domainsconstructor argument, andblocked_domains()
andset_blocked_domains()
methods (and the corresponding argument and methodsforallowed_domains). If you set an allowlist, you can turn it off again bysetting it toNone
.
Domains in block or allow lists that do not start with a dot must equal thecookie domain to be matched. For example,"example.com"
matches a blocklistentry of"example.com"
, but"www.example.com"
does not. Domains that dostart with a dot are matched by more specific domains too. For example, both"www.example.com"
and"www.coyote.example.com"
match".example.com"
(but"example.com"
itself does not). IP addresses are an exception, andmust match exactly. For example, if blocked_domains contains"192.168.1.2"
and".168.1.2"
, 192.168.1.2 is blocked, but 193.168.1.2 is not.
DefaultCookiePolicy
implements the following additional methods:
- DefaultCookiePolicy.blocked_domains()¶
Return the sequence of blocked domains (as a tuple).
- DefaultCookiePolicy.set_blocked_domains(blocked_domains)¶
Set the sequence of blocked domains.
- DefaultCookiePolicy.is_blocked(domain)¶
Return
True
ifdomain is on the blocklist for setting or receivingcookies.
- DefaultCookiePolicy.set_allowed_domains(allowed_domains)¶
Set the sequence of allowed domains, or
None
.
- DefaultCookiePolicy.is_not_allowed(domain)¶
Return
True
ifdomain is not on the allowlist for setting or receivingcookies.
DefaultCookiePolicy
instances have the following attributes, which areall initialised from the constructor arguments of the same name, and which mayall be assigned to.
- DefaultCookiePolicy.rfc2109_as_netscape¶
If true, request that the
CookieJar
instance downgradeRFC 2109 cookies(ie. cookies received in aSet-Cookie header with a versioncookie-attribute of 1) to Netscape cookies by setting the version attribute oftheCookie
instance to 0. The default value isNone
, in whichcase RFC 2109 cookies are downgraded if and only ifRFC 2965 handling is turnedoff. Therefore, RFC 2109 cookies are downgraded by default.
General strictness switches:
- DefaultCookiePolicy.strict_domain¶
Don't allow sites to set two-component domains with country-code top-leveldomains like
.co.uk
,.gov.uk
,.co.nz
.etc. This is far from perfectand isn't guaranteed to work!
RFC 2965 protocol strictness switches:
- DefaultCookiePolicy.strict_rfc2965_unverifiable¶
FollowRFC 2965 rules on unverifiable transactions (usually, an unverifiabletransaction is one resulting from a redirect or a request for an image hosted onanother site). If this is false, cookies arenever blocked on the basis ofverifiability
Netscape protocol strictness switches:
- DefaultCookiePolicy.strict_ns_unverifiable¶
ApplyRFC 2965 rules on unverifiable transactions even to Netscape cookies.
- DefaultCookiePolicy.strict_ns_domain¶
Flags indicating how strict to be with domain-matching rules for Netscapecookies. See below for acceptable values.
- DefaultCookiePolicy.strict_ns_set_initial_dollar¶
Ignore cookies in Set-Cookie: headers that have names starting with
'$'
.
- DefaultCookiePolicy.strict_ns_set_path¶
Don't allow setting cookies whose path doesn't path-match request URI.
strict_ns_domain
is a collection of flags. Its value is constructed byor-ing together (for example,DomainStrictNoDots|DomainStrictNonDomain
meansboth flags are set).
- DefaultCookiePolicy.DomainStrictNoDots¶
When setting cookies, the 'host prefix' must not contain a dot (eg.
www.foo.bar.com
can't set a cookie for.bar.com
, becausewww.foo
contains a dot).
- DefaultCookiePolicy.DomainStrictNonDomain¶
Cookies that did not explicitly specify a
domain
cookie-attribute can onlybe returned to a domain equal to the domain that set the cookie (eg.spam.example.com
won't be returned cookies fromexample.com
that had nodomain
cookie-attribute).
The following attributes are provided for convenience, and are the most usefulcombinations of the above flags:
- DefaultCookiePolicy.DomainLiberal¶
Equivalent to 0 (ie. all of the above Netscape domain strictness flags switchedoff).
- DefaultCookiePolicy.DomainStrict¶
等價於
DomainStrictNoDots|DomainStrictNonDomain
。
Cookie 物件¶
Cookie
instances have Python attributes roughly corresponding to thestandard cookie-attributes specified in the various cookie standards. Thecorrespondence is not one-to-one, because there are complicated rules forassigning default values, because themax-age
andexpires
cookie-attributes contain equivalent information, and becauseRFC 2109 cookiesmay be 'downgraded' byhttp.cookiejar
from version 1 to version 0 (Netscape)cookies.
Assignment to these attributes should not be necessary other than in rarecircumstances in aCookiePolicy
method. The class does not enforceinternal consistency, so you should know what you're doing if you do that.
- Cookie.version¶
Integer or
None
. Netscape cookies haveversion
0.RFC 2965 andRFC 2109 cookies have aversion
cookie-attribute of 1. However, note thathttp.cookiejar
may 'downgrade' RFC 2109 cookies to Netscape cookies, in whichcaseversion
is 0.
- Cookie.name¶
Cookie name (a string).
- Cookie.domain¶
Cookie domain (a string).
- Cookie.path¶
Cookie path (a string, eg.
'/acme/rocket_launchers'
).
- Cookie.secure¶
True
if cookie should only be returned over a secure connection.
- Cookie.expires¶
Integer expiry date in seconds since epoch, or
None
. See also theis_expired()
method.
- Cookie.discard¶
True
if this is a session cookie.
- Cookie.comment_url¶
URL linking to a comment from the server explaining the function of this cookie,or
None
.
- Cookie.rfc2109¶
True
if this cookie was received as anRFC 2109 cookie (ie. the cookiearrived in aSet-Cookie header, and the value of the Versioncookie-attribute in that header was 1). This attribute is provided becausehttp.cookiejar
may 'downgrade' RFC 2109 cookies to Netscape cookies, inwhich caseversion
is 0.
- Cookie.port_specified¶
True
if a port or set of ports was explicitly specified by the server (in theSet-Cookie /Set-Cookie2 header).
- Cookie.domain_specified¶
True
if a domain was explicitly specified by the server.
- Cookie.domain_initial_dot¶
True
if the domain explicitly specified by the server began with a dot('.'
).
Cookies may have additional non-standard cookie-attributes. These may beaccessed using the following methods:
- Cookie.has_nonstandard_attr(name)¶
Return
True
if cookie has the named cookie-attribute.
- Cookie.get_nonstandard_attr(name,default=None)¶
If cookie has the named cookie-attribute, return its value. Otherwise, returndefault.
- Cookie.set_nonstandard_attr(name,value)¶
Set the value of the named cookie-attribute.
TheCookie
class also defines the following method:
- Cookie.is_expired(now=None)¶
True
if cookie has passed the time at which the server requested it shouldexpire. Ifnow is given (in seconds since the epoch), return whether thecookie has expired at the specified time.
範例¶
The first example shows the most common usage ofhttp.cookiejar
:
importhttp.cookiejar,urllib.requestcj=http.cookiejar.CookieJar()opener=urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))r=opener.open("http://example.com/")
This example illustrates how to open a URL using your Netscape, Mozilla, or Lynxcookies (assumes Unix/Netscape convention for location of the cookies file):
importos,http.cookiejar,urllib.requestcj=http.cookiejar.MozillaCookieJar()cj.load(os.path.join(os.path.expanduser("~"),".netscape","cookies.txt"))opener=urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))r=opener.open("http://example.com/")
The next example illustrates the use ofDefaultCookiePolicy
. Turn onRFC 2965 cookies, be more strict about domains when setting and returningNetscape cookies, and block some domains from setting cookies or having themreturned:
importurllib.requestfromhttp.cookiejarimportCookieJar,DefaultCookiePolicypolicy=DefaultCookiePolicy(rfc2965=True,strict_ns_domain=Policy.DomainStrict,blocked_domains=["ads.net",".ads.net"])cj=CookieJar(policy)opener=urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))r=opener.open("http://example.com/")