Python Library Reference——urlparse

时间：2006-09-09 来源：linxh

urlparse -- Parse URLs into components

This module defines a standard interface to break Uniform Resource Locator (URL) strings up in components (addressing scheme, network location, path etc.), to combine the components back into a URL string, and to convert a ``relative URL'' to an absolute URL given a ``base URL.''

The module has been designed to match the Internet RFC on Relative Uniform Resource Locators (and discovered a bug in an earlier draft!). It supports the following URL schemes: file, ftp, gopher, hdl, http, https, imap, mailto, mms, news, nntp, prospero, rsync, rtsp, rtspu, shttp, sip, snews, svn, svn+ssh, telnet, wais.

The urlparse module defines the following functions:

urlparse(

urlstring[, default_scheme[, allow_fragments]])

Parse a URL into 6 components, returning a 6-tuple: (addressing scheme, network location, path, parameters, query, fragment identifier). This corresponds to the general structure of a URL: scheme://netloc/path;parameters?query#fragment. Each tuple item is a string, possibly empty. The components are not broken up in smaller parts (e.g. the network location is a single string), and % escapes are not expanded. The delimiters as shown above are not part of the tuple items, except for a leading slash in the path component, which is retained if present.

Example:

urlparse('http://www.cwi.nl:80/%7Eguido/Python.html')

yields the tuple

('http', 'www.cwi.nl:80', '/%7Eguido/Python.html', '', '', '')

If the default_scheme argument is specified, it gives the default addressing scheme, to be used only if the URL string does not specify one. The default value for this argument is the empty string.

If the allow_fragments argument is zero, fragment identifiers are not allowed, even if the URL's addressing scheme normally does support them. The default value for this argument is 1.

urlunparse(

tuple)

Construct a URL string from a tuple as returned by urlparse(). This may result in a slightly different, but equivalent URL, if the URL that was parsed originally had redundant delimiters, e.g. a ? with an empty query (the draft states that these are equivalent).

urlsplit(

urlstring[, default_scheme[, allow_fragments]])

This is similar to urlparse(), but does not split the params from the URL. This should generally be used instead of urlparse() if the more recent URL syntax allowing parameters to be applied to each segment of the path portion of the URL (see RFC 2396) is wanted. A separate function is needed to separate the path segments and parameters. This function returns a 5-tuple: (addressing scheme, network location, path, query, fragment identifier). New in version 2.2.

urlunsplit(

tuple)

Combine the elements of a tuple as returned by urlsplit() into a complete URL as a string. New in version 2.2.

urljoin(

base, url[, allow_fragments])

Construct a full (``absolute'') URL by combining a ``base URL'' (base) with a ``relative URL'' (url). Informally, this uses components of the base URL, in particular the addressing scheme, the network location and (part of) the path, to provide missing components in the relative URL.

Example:

urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')

yields the string

'http://www.cwi.nl/%7Eguido/FAQ.html'

The allow_fragments argument has the same meaning as for urlparse().

urldefrag(

url)

If url contains a fragment identifier, returns a modified version of url with no fragment identifier, and the fragment identifier as a separate string. If there is no fragment identifier in url, returns url unmodified and an empty string.