Update of /cvsroot/python/python/dist/src/Doc/lib In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv27715/Doc/lib Modified Files: lib.tex libcookie.tex liburllib2.tex Added Files: libcookielib.tex Log Message: Patch #963318: Add support for client-side cookie management. --- NEW FILE: libcookielib.tex --- \section{\module{cookielib} --- Cookie handling for HTTP clients} \declaremodule{standard}{cookielib} \moduleauthor{John J. Lee}{jjl@pobox.com} \sectionauthor{John J. Lee}{jjl@pobox.com} \modulesynopsis{Cookie handling for HTTP clients} The \module{cookielib} module defines classes for automatic handling of HTTP cookies. It is useful for accessing web sites that require small pieces of data -- \dfn{cookies} -- to be set on the client machine by an HTTP response from a web server, and then returned to the server in later HTTP requests. Both the regular Netscape cookie protocol and the protocol defined by \rfc{2965} are handled. RFC 2965 handling is switched off by default. \rfc{2109} cookies are parsed as Netscape cookies and subsequently treated as RFC 2965 cookies. Note that the great majority of cookies on the Internet are Netscape cookies. \module{cookielib} attempts to follow the de-facto Netscape cookie protocol (which differs substantially from that set out in the original Netscape specification), including taking note of the \code{max-age} and \code{port} cookie-attributes introduced with RFC 2109. \note{The various named parameters found in \mailheader{Set-Cookie} and \mailheader{Set-Cookie2} headers (eg. \code{domain} and \code{expires}) are conventionally referred to as \dfn{attributes}. To distinguish them from Python attributes, the documentation for this module uses the term \dfn{cookie-attribute} instead}. The module defines the following exception: \begin{excdesc}{LoadError} Instances of \class{FileCookieJar} raise this exception on failure to load cookies from a file. \end{excdesc} The following classes are provided: \begin{classdesc}{CookieJar}{policy=\constant{None}} \var{policy} is an object implementing the \class{CookiePolicy} interface. The \class{CookieJar} class stores HTTP cookies. It extracts cookies from HTTP requests, and returns them in HTTP responses. \class{CookieJar} instances automatically expire contained cookies when necessary. Subclasses are also responsible for storing and retrieving cookies from a file or database. \end{classdesc} \begin{classdesc}{FileCookieJar}{filename, delayload=\constant{None}, policy=\constant{None}} \var{policy} is an object implementing the \class{CookiePolicy} interface. For the other arguments, see the documentation for the corresponding attributes. A \class{CookieJar} which can load cookies from, and perhaps save cookies to, a file on disk. Cookies are \strong{NOT} loaded from the named file until either the \method{load()} or \method{revert()} method is called. Subclasses of this class are documented in section \ref{file-cookie-jar-classes}. \end{classdesc} \begin{classdesc}{CookiePolicy}{} This class is responsible for deciding whether each cookie should be accepted from / returned to the server. \end{classdesc} \begin{classdesc}{DefaultCookiePolicy}{ blocked_domains=\constant{None}, allowed_domains=\constant{None}, netscape=\constant{True}, rfc2965=\constant{False}, hide_cookie2=\constant{False}, strict_domain=\constant{False}, strict_rfc2965_unverifiable=\constant{True}, strict_ns_unverifiable=\constant{False}, strict_ns_domain=\constant{DefaultCookiePolicy.DomainLiberal}, strict_ns_set_initial_dollar=\constant{False}, strict_ns_set_path=\constant{False} } Constructor arguments should be passed as keyword arguments only. \var{blocked_domains} is a sequence of domain names that we never accept cookies from, nor return cookies to. \var{allowed_domains} if not \constant{None}, this is a sequence of the only domains for which we accept and return cookies. For all other arguments, see the documentation for \class{CookiePolicy} and \class{DefaultCookiePolicy} objects. \class{DefaultCookiePolicy} implements the standard accept / reject rules for Netscape and RFC 2965 cookies. RFC 2109 cookies (ie. cookies received in a \mailheader{Set-Cookie} header with a version cookie-attribute of 1) are treated according to the RFC 2965 rules. \class{DefaultCookiePolicy} also provides some parameters to allow some fine-tuning of policy. \end{classdesc} \begin{classdesc}{Cookie}{} This class represents Netscape, RFC 2109 and RFC 2965 cookies. It is not expected that users of \module{cookielib} construct their own \class{Cookie} instances. Instead, if necessary, call \method{make_cookies()} on a \class{CookieJar} instance. \end{classdesc} \begin{seealso} \seemodule{urllib2}{URL opening with automatic cookie handling.} \seemodule{Cookie}{HTTP cookie classes, principally useful for server-side code. The \module{cookielib} and \module{Cookie} modules do not depend on each other.} \seeurl{http://wwwsearch.sf.net/ClientCookie/}{Extensions to this module, including a class for reading Microsoft Internet Explorer cookies on Windows.} \seeurl{http://www.netscape.com/newsref/std/cookie_spec.html}{The specification of the original Netscape cookie protocol. Though this is still the dominant protocol, the 'Netscape cookie protocol' implemented by all the major browsers (and \module{cookielib}) only bears a passing resemblance to the one sketched out in \code{cookie_spec.html}.} \seerfc{2109}{HTTP State Management Mechanism}{Obsoleted by RFC 2965. Uses \mailheader{Set-Cookie} with version=1.} \seerfc{2965}{HTTP State Management Mechanism}{The Netscape protocol with the bugs fixed. Uses \mailheader{Set-Cookie2} in place of \mailheader{Set-Cookie}. Not widely used.} \seeurl{http://kristol.org/cookie/errata.html}{Unfinished errata to RFC 2965.} \seerfc{2964}{Use of HTTP State Management}{} \end{seealso} \subsection{CookieJar and FileCookieJar Objects \label{cookie-jar-objects}} \class{CookieJar} objects support the iterator protocol. \class{CookieJar} has the following methods: \begin{methoddesc}[CookieJar]{add_cookie_header}{request} Add correct \mailheader{Cookie} header to \var{request}. If the CookiePolicy allows (ie. the \class{CookiePolicy} instance's \member{rfc2965} and \member{hide_cookie2} attributes are true and false respectively), the \mailheader{Cookie2} header is also added when appropriate. The \var{request} object (usually a \class{urllib2.Request} instance) must support the methods \method{get_full_url()}, \method{get_host()}, \method{get_type()}, \method{unverifiable()}, \method{get_origin_req_host()}, \method{has_header()}, \method{get_header()}, \method{header_items()}, and \method{add_unredirected_header()},as documented by \module{urllib2}. \end{methoddesc} \begin{methoddesc}[CookieJar]{extract_cookies}{response, request} Extract cookies from HTTP \var{response} and store them in the \class{CookieJar}, where allowed by policy. The \class{CookieJar} will look for allowable \mailheader{Set-Cookie} and \mailheader{Set-Cookie2} headers in the \var{response} argument, and store cookies as appropriate (subject to the \method{CookiePolicy.set_ok()} method's approval). The \var{response} object (usually the result of a call to \method{urllib2.urlopen()}, or similar) should support an \method{info()} method, which returns an object with a \method{getallmatchingheaders()} method (usually a \class{mimetools.Message} instance). The \var{request} object (usually a \class{urllib2.Request} instance) must support the methods \method{get_full_url()}, \method{get_host()}, \method{unverifiable()}, and \method{get_origin_req_host()}, as documented by \module{urllib2}. The request is used to set default values for cookie-attributes as well as for checking that the cookie is allowed to be set. \end{methoddesc} \begin{methoddesc}[CookieJar]{set_policy}{policy} Set the \class{CookiePolicy} instance to be used. \end{methoddesc} \begin{methoddesc}[CookieJar]{make_cookies}{response, request} Return sequence of \class{Cookie} objects extracted from \var{response} object. See the documentation for \method{extract_cookies} for the interfaces required of the \var{response} and \var{request} arguments. \end{methoddesc} \begin{methoddesc}[CookieJar]{set_cookie_if_ok}{cookie, request} Set a \class{Cookie} if policy says it's OK to do so. \end{methoddesc} \begin{methoddesc}[CookieJar]{set_cookie}{cookie} Set a \class{Cookie}, without checking with policy to see whether or not it should be set. \end{methoddesc} \begin{methoddesc}[CookieJar]{clear}{\optional{domain\optional{, path\optional{, name}}}} Clear some cookies. If invoked without arguments, clear all cookies. If given a single argument, only cookies belonging to that \var{domain} will be removed. If given two arguments, cookies belonging to the specified \var{domain} and URL \var{path} are removed. If given three arguments, then the cookie with the specified \var{domain}, \var{path} and \var{name} is removed. Raises \exception{KeyError} if no matching cookie exists. \end{methoddesc} \begin{methoddesc}[CookieJar]{clear_session_cookies}{} Discard all session cookies. Discards all contained cookies that have a true \member{discard} attribute (usually because they had either no \code{max-age} or \code{expires} cookie-attribute, or an explicit \code{discard} cookie-attribute). For interactive browsers, the end of a session usually corresponds to closing the browser window. Note that the \method{save()} method won't save session cookies anyway, unless you ask otherwise by passing a true \var{ignore_discard} argument. \end{methoddesc} \class{FileCookieJar} implements the following additional methods: \begin{methoddesc}[FileCookieJar]{save}{filename=\constant{None}, ignore_discard=\constant{False}, ignore_expires=\constant{False}} Save cookies to a file. This base class raises \class{NotImplementedError}. Subclasses may leave this method unimplemented. \var{filename} is the name of file in which to save cookies. If \var{filename} is not specified, \member{self.filename} is used (whose default is the value passed to the constructor, if any); if \member{self.filename} is \constant{None}, \exception{ValueError} is raised. \var{ignore_discard}: save even cookies set to be discarded. \var{ignore_expires}: save even cookies that have expired The file is overwritten if it already exists, thus wiping all the cookies it contains. Saved cookies can be restored later using the \method{load()} or \method{revert()} methods. \end{methoddesc} \begin{methoddesc}[FileCookieJar]{load}{filename=\constant{None}, ignore_discard=\constant{False}, ignore_expires=\constant{False}} Load cookies from a file. Old cookies are kept unless overwritten by newly loaded ones. Arguments are as for \method{save()}. The named file must be in the format understood by the class, or \exception{LoadError} will be raised. \end{methoddesc} \begin{methoddesc}[FileCookieJar]{revert}{filename=\constant{None}, ignore_discard=\constant{False}, ignore_expires=\constant{False}} Clear all cookies and reload cookies from a saved file. Raises \exception{cookielib.LoadError} or \exception{IOError} if reversion is not successful; the object's state will not be altered if this happens. \end{methoddesc} \class{FileCookieJar} instances have the following public attributes: \begin{memberdesc}{filename} Filename of default file in which to keep cookies. \end{memberdesc} \begin{memberdesc}{delayload} If true, load cookies lazily from disk. This is only a hint, since this only affects performance, not behaviour (unless the cookies on disk are changing). A \class{CookieJar} object may ignore it. None of the \class{FileCookieJar} classes included in the standard library lazily loads cookies. \end{memberdesc} \subsection{FileCookieJar subclasses and co-operation with web browsers \label{file-cookie-jar-classes}} The following \class{CookieJar} subclasses are provided for reading and writing . Further \class{CookieJar} subclasses, including one that reads Microsoft Internet Explorer cookies, are available at \url{http://wwwsearch.sf.net/ClientCookie/}. \begin{classdesc}{MozillaCookieJar}{filename, delayload=\constant{None}, policy=\constant{None}} A \class{FileCookieJar} that can load from and save cookies to disk in the Mozilla \code{cookies.txt} file format (which is also used by the lynx and Netscape browsers). \note{This loses information about RFC 2965 cookies, and also about newer or non-standard cookie-attributes such as \code{port}.} \warning{Back up your cookies before saving if you have cookies whose loss / corruption would be inconvenient (there are some subtleties which may lead to slight changes in the file over a load / save round-trip).} Also note that cookies saved while Mozilla is running will get clobbered by Mozilla. \end{classdesc} \begin{classdesc}{LWPCookieJar}{filename, delayload=\constant{None}, policy=\constant{None}} A \class{FileCookieJar} that can load from and save cookies to disk in format compatible with the libwww-perl library's \code{Set-Cookie3} file format. This is convenient if you want to store cookies in a human-readable file. \end{classdesc} \subsection{CookiePolicy Objects \label{cookie-policy-objects}} Objects implementing the \class{CookiePolicy} interface have the following methods: \begin{methoddesc}[CookiePolicy]{set_ok}{cookie, request} Return boolean value indicating whether cookie should be accepted from server. \var{cookie} is a \class{cookielib.Cookie} instance. \var{request} is an object implementing the interface defined by the documentation for \method{CookieJar.extract_cookies()}. \end{methoddesc} \begin{methoddesc}[CookiePolicy]{return_ok}{cookie, request} Return boolean value indicating whether cookie should be returned to server. \var{cookie} is a \class{cookielib.Cookie} instance. \var{request} is an object implementing the interface defined by the documentation for \method{CookieJar.add_cookie_header()}. \end{methoddesc} \begin{methoddesc}[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 cookie with a particular domain (which might involve reading many files). The default implementations of \method{domain_return_ok()} and \method{path_return_ok()} (\samp{return True}) leave all the work to \method{return_ok()}. If \method{domain_return_ok()} returns true for the cookie domain, \method{path_return_ok()} is called for the cookie path. Otherwise, \method{path_return_ok()} and \method{return_ok()} are never called for that cookie domain. If \method{path_return_ok()} returns true, \method{return_ok()} is called with the \class{Cookie} object itself for a full check. Otherwise, \method{return_ok()} is never called for that cookie path. Note that \method{domain_return_ok()} is called for every \emph{cookie} domain, not just for the \emph{request} domain. For example, the function might be called with both \code{".example.com"} and \code{"www.example.com"} if the request domain is \code{"www.example.com"}. The same goes for \method{path_return_ok()}. The \var{request} argument is as documented for \method{return_ok()}. \end{methoddesc} \begin{methoddesc}[CookiePolicy]{path_return_ok}{path, request} Return false if cookies should not be returned, given cookie path. See the documentation for \method{domain_return_ok()}. \end{methoddesc} In addition to implementing the methods above, implementations of the \class{CookiePolicy} interface must also supply the following attributes, indicating which protocols should be used, and how. All of these attributes may be assigned to. \begin{memberdesc}{netscape} Implement netscape protocol. \end{memberdesc} \begin{memberdesc}{rfc2965} Implement RFC 2965 protocol. \end{memberdesc} \begin{memberdesc}{hide_cookie2} Don't add Cookie2 header to requests (the presence of this header indicates to the server that we understand RFC 2965 cookies). \end{memberdesc} The most useful way to define a \class{CookiePolicy} class is by subclassing from \class{DefaultCookiePolicy} and overriding some or all of the methods above. \class{CookiePolicy} itself may be used as a 'null policy' to allow setting and receiving any and all cookies. \subsection{DefaultCookiePolicy Objects \label{default-cookie-policy-objects}} Implements the standard rules for accepting and returning cookies. Both RFC 2965 and Netscape cookies are covered. RFC 2965 handling is switched off by default. The easiest way to provide your own policy is to override this class and call its methods in your overriden implementations before adding your own additional checks: \begin{verbatim} import cookielib class MyCookiePolicy(cookielib.DefaultCookiePolicy): def set_ok(self, cookie, request): if not cookielib.DefaultCookiePolicy.set_ok(self, cookie, request): return False if i_dont_want_to_store_this_cookie(cookie): return False return True \end{verbatim} In addition to the features required to implement the \class{CookiePolicy} interface, this class allows you to block and allow domains from setting and receiving cookies. There are also some strictness switches that allow you to tighten up the rather loose Netscape protocol rules a little bit (at the cost of blocking some benign cookies). A domain blacklist and whitelist is provided (both off by default). Only domains not in the blacklist and present in the whitelist (if the whitelist is active) participate in cookie setting and returning. Use the \var{blocked_domains} constructor argument, and \method{blocked_domains()} and \method{set_blocked_domains()} methods (and the corresponding argument and methods for \var{allowed_domains}). If you set a whitelist, you can turn it off again by setting it to \constant{None}. Domains in block or allow lists that do not start with a dot must be equal. For example, \code{"example.com"} matches a blacklist entry of \code{"example.com"}, but \code{"www.example.com"} does not. Domains that do start with a dot are matched by more specific domains too. For example, both \code{"www.example.com"} and \code{"www.coyote.example.com"} match \code{".example.com"} (but \code{"example.com"} itself does not). IP addresses are an exception, and must match exactly. For example, if blocked_domains contains \code{"192.168.1.2"} and \code{".168.1.2"}, 192.168.1.2 is blocked, but 193.168.1.2 is not. \class{DefaultCookiePolicy} implements the following additional methods: \begin{methoddesc}[DefaultCookiePolicy]{blocked_domains}{} Return the sequence of blocked domains (as a tuple). \end{methoddesc} \begin{methoddesc}[DefaultCookiePolicy]{set_blocked_domains} {blocked_domains} Set the sequence of blocked domains. \end{methoddesc} \begin{methoddesc}[DefaultCookiePolicy]{is_blocked}{domain} Return whether \var{domain} is on the blacklist for setting or receiving cookies. \end{methoddesc} \begin{methoddesc}[DefaultCookiePolicy]{allowed_domains}{} Return \constant{None}, or the sequence of allowed domains (as a tuple). \end{methoddesc} \begin{methoddesc}[DefaultCookiePolicy]{set_allowed_domains} {allowed_domains} Set the sequence of allowed domains, or \constant{None}. \end{methoddesc} \begin{methoddesc}[DefaultCookiePolicy]{is_not_allowed}{domain} Return whether \var{domain} is not on the whitelist for setting or receiving cookies. \end{methoddesc} \class{DefaultCookiePolicy} instances have the following attributes, which are all initialised from the constructor arguments of the same name, and which may all be assigned to. General strictness switches: \begin{memberdesc}{strict_domain} Don't allow sites to set two-component domains with country-code top-level domains like \code{.co.uk}, \code{.gov.uk}, \code{.co.nz}.etc. This is far from perfect and isn't guaranteed to work! \end{memberdesc} RFC 2965 protocol strictness switches: \begin{memberdesc}{strict_rfc2965_unverifiable} Follow RFC 2965 rules on unverifiable transactions (usually, an unverifiable transaction is one resulting from a redirect or a request for an image hosted on another site). If this is false, cookies are \emph{never} blocked on the basis of verifiability \end{memberdesc} Netscape protocol strictness switches: \begin{memberdesc}{strict_ns_unverifiable} apply RFC 2965 rules on unverifiable transactions even to Netscape cookies \end{memberdesc} \begin{memberdesc}{strict_ns_domain} Flags indicating how strict to be with domain-matching rules for Netscape cookies. See below for acceptable values. \end{memberdesc} \begin{memberdesc}{strict_ns_set_initial_dollar} Ignore cookies in Set-Cookie: headers that have names starting with \code{'\$'}. \end{memberdesc} \begin{memberdesc}{strict_ns_set_path} Don't allow setting cookies whose path doesn't path-match request URI. \end{memberdesc} \member{strict_ns_domain} is a collection of flags. Its value is constructed by or-ing together (for example, \code{DomainStrictNoDots|DomainStrictNonDomain} means both flags are set). \begin{memberdesc}{DomainStrictNoDots} When setting cookies, the 'host prefix' must not contain a dot (eg. \code{www.foo.bar.com} can't set a cookie for \code{.bar.com}, because \code{www.foo} contains a dot). \end{memberdesc} \begin{memberdesc}{DomainStrictNonDomain} Cookies that did not explicitly specify a \code{domain} cookie-attribute can only be returned to a domain that string-compares equal to the domain that set the cookie (eg. \code{spam.example.com} won't be returned cookies from \code{example.com} that had no \code{domain} cookie-attribute). \end{memberdesc} \begin{memberdesc}{DomainRFC2965Match} When setting cookies, require a full RFC 2965 domain-match. \end{memberdesc} The following attributes are provided for convenience, and are the most useful combinations of the above flags: \begin{memberdesc}{DomainLiberal} Equivalent to 0 (ie. all of the above Netscape domain strictness flags switched off). \end{memberdesc} \begin{memberdesc}{DomainStrict} Equivalent to \code{DomainStrictNoDots|DomainStrictNonDomain}. \end{memberdesc} \subsection{Cookie Objects \label{cookie-jar-objects}} \class{Cookie} instances have Python attributes roughly corresponding to the standard cookie-attributes specified in the various cookie standards. The correspondence is not one-to-one, because there are complicated rules for assigning default values, and because the \code{max-age} and \code{expires} cookie-attributes contain equivalent information. Assignment to these attributes should not be necessary other than in rare circumstances in a \class{CookiePolicy} method. The class does not enforce internal consistency, so you should know what you're doing if you do that. \begin{memberdesc}[Cookie]{version} Integer or \constant{None}. Netscape cookies have version 0. RFC 2965 and RFC 2109 cookies have version 1. \end{memberdesc} \begin{memberdesc}[Cookie]{name} Cookie name (a string), or \constant{None}. \end{memberdesc} \begin{memberdesc}[Cookie]{value} Cookie value (a string). \end{memberdesc} \begin{memberdesc}[Cookie]{port} String representing a port or a set of ports (eg. '80', or '80,8080'), or \constant{None}. \end{memberdesc} \begin{memberdesc}[Cookie]{path} Cookie path (a string, eg. '/acme/rocket_launchers'). \end{memberdesc} \begin{memberdesc}[Cookie]{secure} True if cookie should only be returned over a secure connection. \end{memberdesc} \begin{memberdesc}[Cookie]{expires} Integer expiry date in seconds since epoch, or \constant{None}. See also the \method{is_expired()} method. \end{memberdesc} \begin{memberdesc}[Cookie]{discard} True if this is a session cookie. \end{memberdesc} \begin{memberdesc}[Cookie]{comment} String comment from the server explaining the function of this cookie, or \constant{None}. \end{memberdesc} \begin{memberdesc}[Cookie]{comment_url} URL linking to a comment from the server explaining the function of this cookie, or \constant{None}. \end{memberdesc} \begin{memberdesc}[Cookie]{port_specified} True if a port or set of ports was explicitly specified by the server (in the \mailheader{Set-Cookie} / \mailheader{Set-Cookie2} header). \end{memberdesc} \begin{memberdesc}[Cookie]{domain_specified} True if a domain was explicitly specified by the server. \end{memberdesc} \begin{memberdesc}[Cookie]{domain_initial_dot} True if the domain explicitly specified by the server began with a dot ('.'). \end{memberdesc} Cookies may have additional non-standard cookie-attributes. These may be accessed using the following methods: \begin{methoddesc}[Cookie]{has_nonstandard_attr}{name} Return true if cookie has the named cookie-attribute. \end{methoddesc} \begin{methoddesc}[Cookie]{get_nonstandard_attr}{name, default=\constant{None}} If cookie has the named cookie-attribute, return its value. Otherwise, return \var{default}. \end{methoddesc} \begin{methoddesc}[Cookie]{set_nonstandard_attr}{name, value} Set the value of the named cookie-attribute. \end{methoddesc} The \class{Cookie} class also defines the following method: \begin{methoddesc}[Cookie]{is_expired}{\optional{now=\constant{None}}} True if cookie has passed the time at which the server requested it should expire. If \var{now} is given (in seconds since the epoch), return whether the cookie has expired at the specified time. \end{methoddesc} \subsection{Examples \label{cookielib-examples}} The first example shows the most common usage of \module{cookielib}: \begin{verbatim} import cookielib, urllib2 cj = cookielib.CookieJar() opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") \end{verbatim} This example illustrates how to open a URL using your Netscape, Mozilla, or lynx cookies (assumes \UNIX{} convention for location of the cookies file): \begin{verbatim} import os, cookielib, urllib2 cj = cookielib.MozillaCookieJar() cj.load(os.path.join(os.environ["HOME"], "/.netscape/cookies.txt")) opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") \end{verbatim} The next example illustrates the use of \class{DefaultCookiePolicy}. Turn on RFC 2965 cookies, be more strict about domains when setting and returning Netscape cookies, and block some domains from setting cookies or having them returned: \begin{verbatim} import urllib2 from cookielib import CookieJar, DefaultCookiePolicy as Policy policy = Policy(rfc2965=True, strict_ns_domain=Policy.DomainStrict, blocked_domains=["ads.net", ".ads.net"]) cj = CookieJar(policy) opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) r = opener.open("http://example.com/") \end{verbatim} Index: lib.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/lib.tex,v retrieving revision 1.225 retrieving revision 1.226 diff -C2 -d -r1.225 -r1.226 *** lib.tex 29 Jan 2004 07:35:45 -0000 1.225 --- lib.tex 31 May 2004 18:22:39 -0000 1.226 *************** *** 234,237 **** --- 234,238 ---- \input{libsimplehttp} \input{libcgihttp} + \input{libcookielib} \input{libcookie} \input{libxmlrpclib} Index: libcookie.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/libcookie.tex,v retrieving revision 1.11 retrieving revision 1.12 diff -C2 -d -r1.11 -r1.12 *** libcookie.tex 25 Aug 2003 04:28:03 -0000 1.11 --- libcookie.tex 31 May 2004 18:22:39 -0000 1.12 *************** *** 69,72 **** --- 69,76 ---- \begin{seealso} + \seemodule{cookielib}{HTTP cookie handling for for web + \emph{clients}. The \module{cookielib} and \module{Cookie} + modules do not depend on each other.} + \seerfc{2109}{HTTP State Management Mechanism}{This is the state management specification implemented by this module.} Index: liburllib2.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/liburllib2.tex,v retrieving revision 1.17 retrieving revision 1.18 diff -C2 -d -r1.17 -r1.18 *** liburllib2.tex 12 May 2004 03:07:27 -0000 1.17 --- liburllib2.tex 31 May 2004 18:22:39 -0000 1.18 *************** *** 11,15 **** The \module{urllib2} module defines functions and classes which help in opening URLs (mostly HTTP) in a complex world --- basic and digest ! authentication, redirections and more. The \module{urllib2} module defines the following functions: --- 11,15 ---- The \module{urllib2} module defines functions and classes which help in opening URLs (mostly HTTP) in a complex world --- basic and digest ! authentication, redirections, cookies and more. The \module{urllib2} module defines the following functions: *************** *** 17,22 **** \begin{funcdesc}{urlopen}{url\optional{, data}} Open the URL \var{url}, which can be either a string or a \class{Request} ! object (currently the code checks that it really is a \class{Request} ! instance, or an instance of a subclass of \class{Request}). \var{data} should be a string, which specifies additional data to --- 17,21 ---- \begin{funcdesc}{urlopen}{url\optional{, data}} Open the URL \var{url}, which can be either a string or a \class{Request} ! object. \var{data} should be a string, which specifies additional data to *************** *** 88,92 **** The following classes are provided: ! \begin{classdesc}{Request}{url\optional{, data\optional{, headers}}} This class is an abstraction of a URL request. --- 87,92 ---- The following classes are provided: ! \begin{classdesc}{Request}{url\optional{, data}\optional{, headers} ! \optional{, origin_req_host}\optional{, unverifiable}} This class is an abstraction of a URL request. *************** *** 95,98 **** --- 95,116 ---- \var{headers} should be a dictionary, and will be treated as if \method{add_header()} was called with each key and value as arguments. + + The final two arguments are only of interest for correct handling of + third-party HTTP cookies: + + \var{origin_req_host} should be the request-host of the origin + transaction, as defined by \rfc{2965}. It defaults to + \code{cookielib.request_host(self)}. This is the host name or IP + address of the original request that was initiated by the user. For + example, if the request is for an image in an HTML document, this + should be the request-host of the request for the page containing the + image. + + \var{unverifiable} should indicate whether the request is + unverifiable, as defined by RFC 2965. It defaults to False. An + unverifiable request is one whose URL the user did not have the option + to approve. For example, if the request is for an image in an HTML + document, and the user had no option to approve the automatic fetching + of the image, this should be true. \end{classdesc} *************** *** 117,120 **** --- 135,142 ---- \end{classdesc} + \begin{classdesc}{HTTPCookieProcessor}{\optional{cookiejar}} + A class to handle HTTP Cookies. + \end{classdesc} + \begin{classdesc}{ProxyHandler}{\optional{proxies}} Cause requests to go through a proxy. *************** *** 218,225 **** \begin{methoddesc}[Request]{add_data}{data} ! Set the \class{Request} data to \var{data}. This is ignored ! by all handlers except HTTP handlers --- and there it should be an ! \mimetype{application/x-www-form-encoded} buffer, and will change the ! request to be \code{POST} rather than \code{GET}. \end{methoddesc} --- 240,247 ---- \begin{methoddesc}[Request]{add_data}{data} ! Set the \class{Request} data to \var{data}. This is ignored by all ! handlers except HTTP handlers --- and there it should be a byte ! string, and will change the request to be \code{POST} rather than ! \code{GET}. \end{methoddesc} *************** *** 283,286 **** --- 305,319 ---- \end{methoddesc} + \begin{methoddesc}[Request]{get_origin_req_host}{} + Return the request-host of the origin transaction, as defined by + \rfc{2965}. See the documentation for the \class{Request} + constructor. + \end{methoddesc} + + \begin{methoddesc}[Request]{is_unverifiable}{} + Return whether the request is unverifiable, as defined by RFC 2965. + See the documentation for the \class{Request} constructor. + \end{methoddesc} + \subsection{OpenerDirector Objects \label{opener-director-objects}} *************** *** 290,301 **** \begin{methoddesc}[OpenerDirector]{add_handler}{handler} \var{handler} should be an instance of \class{BaseHandler}. The ! following methods are searched, and added to the possible chains. \begin{itemize} \item \method{\var{protocol}_open()} --- signal that the handler knows how to open \var{protocol} URLs. ! \item \method{\var{protocol}_error_\var{type}()} --- ! signal that the handler knows how to handle \var{type} errors from ! \var{protocol}. \item \method{\var{protocol}_request()} --- signal that the handler knows how to pre-process \var{protocol} --- 323,338 ---- \begin{methoddesc}[OpenerDirector]{add_handler}{handler} \var{handler} should be an instance of \class{BaseHandler}. The ! following methods are searched, and added to the possible chains (note ! that HTTP errors are a special case). \begin{itemize} \item \method{\var{protocol}_open()} --- signal that the handler knows how to open \var{protocol} URLs. ! \item \method{http_error_\var{type}()} --- ! signal that the handler knows how to handle HTTP errors with HTTP ! error code \var{type}. ! \item \method{\var{protocol}_error()} --- ! signal that the handler knows how to handle errors from ! (non-\code{http}) \var{protocol}. \item \method{\var{protocol}_request()} --- signal that the handler knows how to pre-process \var{protocol} *************** *** 307,319 **** \end{methoddesc} - \begin{methoddesc}[OpenerDirector]{close}{} - Explicitly break cycles, and delete all the handlers. - Because the \class{OpenerDirector} needs to know the registered handlers, - and a handler needs to know who the \class{OpenerDirector} who called - it is, there is a reference cycle. Even though recent versions of Python - have cycle-collection, it is sometimes preferable to explicitly break - the cycles. - \end{methoddesc} - \begin{methoddesc}[OpenerDirector]{open}{url\optional{, data}} Open the given \var{url} (which can be a request object or a string), --- 344,347 ---- *************** *** 321,330 **** Arguments, return values and exceptions raised are the same as those of \function{urlopen()} (which simply calls the \method{open()} method ! on the default installed \class{OpenerDirector}). \end{methoddesc} \begin{methoddesc}[OpenerDirector]{error}{proto\optional{, arg\optional{, \moreargs}}} ! Handle an error in a given protocol. This will call the registered error handlers for the given protocol with the given arguments (which are protocol specific). The HTTP protocol is a special case which --- 349,358 ---- Arguments, return values and exceptions raised are the same as those of \function{urlopen()} (which simply calls the \method{open()} method ! on the currently installed global \class{OpenerDirector}). \end{methoddesc} \begin{methoddesc}[OpenerDirector]{error}{proto\optional{, arg\optional{, \moreargs}}} ! Handle an error of the given protocol. This will call the registered error handlers for the given protocol with the given arguments (which are protocol specific). The HTTP protocol is a special case which *************** *** 336,339 **** --- 364,406 ---- \end{methoddesc} + OpenerDirector objects open URLs in three stages: + + \begin{enumerate} + \item Every handler with a method named like + \method{\var{protocol}_request()} has that method called to + pre-process the request. + + The order in which these methods are called is determined by + sorting the handler instances by the \member{.processor_order} + attribute. + + \item Handlers with a method named like + \method{\var{protocol}_open()} are called to handle the request. + This stage ends when a handler either returns a + non-\constant{None} value (ie. a response), or raises an exception + (usually URLError). Exceptions are allowed to propagate. + + In fact, the above algorithm is first tried for methods named + \method{default_open}. If all such methods return + \constant{None}, the algorithm is repeated for methods named like + \method{\var{protocol}_open()}. If all such methods return + \constant{None}, the algorithm is repeated for methods named + \method{unknown_open()}. + + Note that the implementation of these methods may involve calls of + the parent \class{OpenerDirector} instance's \method{.open()} and + \method{.error()} methods. + + The order in which these methods are called is determined by + sorting the handler instances. + + \item Every handler with a method named like + \method{\var{protocol}_response()} has that method called to + post-process the response. + + The order in which these methods are called is determined by + sorting the handler instances by the \member{.processor_order} + attribute. + \end{enumerate} \subsection{BaseHandler Objects \label{base-handler-objects}} *************** *** 352,356 **** The following members and methods should only be used by classes ! derived from \class{BaseHandler}: \begin{memberdesc}[BaseHandler]{parent} --- 419,427 ---- The following members and methods should only be used by classes ! derived from \class{BaseHandler}. \note{The convention has been ! adopted that subclasses defining \method{\var{protocol}_request()} or ! \method{\var{protocol}_response()} methods are named ! \class{*Processor}; all others are named \class{*Handler}.} ! \begin{memberdesc}[BaseHandler]{parent} *************** *** 424,427 **** --- 495,521 ---- \end{methoddesc} + \begin{methoddescni}[BaseHandler]{\var{protocol}_request}{req} + This method is \emph{not} defined in \class{BaseHandler}, but + subclasses should define it if they want to pre-process requests of + the given protocol. + + This method, if defined, will be called by the parent + \class{OpenerDirector}. \var{req} will be a \class{Request} object. + The return value should be a \class{Request} object. + \end{methoddescni} + + \begin{methoddescni}[BaseHandler]{\var{protocol}_response}{req, response} + This method is \emph{not} defined in \class{BaseHandler}, but + subclasses should define it if they want to post-process responses of + the given protocol. + + This method, if defined, will be called by the parent + \class{OpenerDirector}. \var{req} will be a \class{Request} object. + \var{response} will be an object implementing the same interface as + the return value of \function{urlopen()}. The return value should + implement the same interface as the return value of + \function{urlopen()}. + \end{methoddescni} + \subsection{HTTPRedirectHandler Objects \label{http-redirect-handler}} *************** *** 435,444 **** Return a \class{Request} or \code{None} in response to a redirect. This is called by the default implementations of the ! \method{http_error_30*()} methods when a redirection is received ! from the server. If a redirection should take place, return a new \class{Request} to allow \method{http_error_30*()} to perform the ! redirect. Otherwise, raise \exception{HTTPError} if no other ! \class{Handler} should try to handle this URL, or return \code{None} ! if you can't but another \class{Handler} might. \begin{notice} --- 529,538 ---- Return a \class{Request} or \code{None} in response to a redirect. This is called by the default implementations of the ! \method{http_error_30*()} methods when a redirection is received from ! the server. If a redirection should take place, return a new \class{Request} to allow \method{http_error_30*()} to perform the ! redirect. Otherwise, raise \exception{HTTPError} if no other handler ! should try to handle this URL, or return \code{None} if you can't but ! another handler might. \begin{notice} *************** *** 479,482 **** --- 573,585 ---- + \subsection{HTTPCookieProcessor Objects \label{http-cookie-processor}} + + \class{HTTPCookieProcessor} instances have one attribute: + + \begin{memberdesc}{cookiejar} + The \class{cookielib.CookieJar} in which cookies are stored. + \end{memberdesc} + + \subsection{ProxyHandler Objects \label{proxy-handler}}