urlparse — Parse URLs into components
Note
The urlparse module is renamed to urllib.parse in Python 3.0.
The 2to3 tool will automatically adapt imports when converting
your sources to 3.0.
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, sftp, shttp, sip, sips,
snews, svn, svn+ssh, telnet, wais.
New in version 2.5: Support for the sftp and sips schemes.
The urlparse module defines the following functions:
-
urlparse.urlparse(urlstring[, default_scheme[, allow_fragments]])
Parse a URL into six components, returning a 6-tuple. 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 (for example, the network location is a single string), and %
escapes are not expanded. The delimiters as shown above are not part of the
result, except for a leading slash in the path component, which is retained if
present. For example:
>>> from urlparse import urlparse
>>> o = urlparse('http://www.cwi.nl:80/%7Eguido/Python.html')
>>> o # doctest: +NORMALIZE_WHITESPACE
ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
params='', query='', fragment='')
>>> o.scheme
'http'
>>> o.port
80
>>> o.geturl()
'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 does not specify one. The default value for
this argument is the empty string.
If the allow_fragments argument is false, fragment identifiers are not
allowed, even if the URL’s addressing scheme normally does support them. The
default value for this argument is True.
The return value is actually an instance of a subclass of tuple. This
class has the following additional read-only convenience attributes:
Attribute |
Index |
Value |
Value if not present |
scheme |
0 |
URL scheme specifier |
empty string |
netloc |
1 |
Network location part |
empty string |
path |
2 |
Hierarchical path |
empty string |
params |
3 |
Parameters for last path
element |
empty string |
query |
4 |
Query component |
empty string |
fragment |
5 |
Fragment identifier |
empty string |
username |
|
User name |
None |
password |
|
Password |
None |
hostname |
|
Host name (lower case) |
None |
port |
|
Port number as integer,
if present |
None |
See section Results of urlparse() and urlsplit() for more information on the result
object.
Changed in version 2.5: Added attributes to return value.
-
urlparse.parse_qs(qs[, keep_blank_values[, strict_parsing]])
Parse a query string given as a string argument (data of type
application/x-www-form-urlencoded). Data are returned as a
dictionary. The dictionary keys are the unique query variable names and the
values are lists of values for each name.
The optional argument keep_blank_values is a flag indicating whether blank
values in URL encoded queries should be treated as blank strings. A true value
indicates that blanks should be retained as blank strings. The default false
value indicates that blank values are to be ignored and treated as if they were
not included.
The optional argument strict_parsing is a flag indicating what to do with
parsing errors. If false (the default), errors are silently ignored. If true,
errors raise a ValueError exception.
Use the urllib.urlencode() function to convert such dictionaries into
query strings.
-
urlparse.parse_qsl(qs[, keep_blank_values[, strict_parsing]])
Parse a query string given as a string argument (data of type
application/x-www-form-urlencoded). Data are returned as a list of
name, value pairs.
The optional argument keep_blank_values is a flag indicating whether blank
values in URL encoded queries should be treated as blank strings. A true value
indicates that blanks should be retained as blank strings. The default false
value indicates that blank values are to be ignored and treated as if they were
not included.
The optional argument strict_parsing is a flag indicating what to do with
parsing errors. If false (the default), errors are silently ignored. If true,
errors raise a ValueError exception.
Use the urllib.urlencode() function to convert such lists of pairs into
query strings.
-
urlparse.urlunparse(parts)
- Construct a URL from a tuple as returned by urlparse(). The parts argument
can be any six-item iterable. This may result in a slightly different, but
equivalent URL, if the URL that was parsed originally had unnecessary delimiters
(for example, a ? with an empty query; the RFC states that these are
equivalent).
-
urlparse.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).
The return value is actually an instance of a subclass of tuple. This
class has the following additional read-only convenience attributes:
Attribute |
Index |
Value |
Value if not present |
scheme |
0 |
URL scheme specifier |
empty string |
netloc |
1 |
Network location part |
empty string |
path |
2 |
Hierarchical path |
empty string |
query |
3 |
Query component |
empty string |
fragment |
4 |
Fragment identifier |
empty string |
username |
|
User name |
None |
password |
|
Password |
None |
hostname |
|
Host name (lower case) |
None |
port |
|
Port number as integer,
if present |
None |
See section Results of urlparse() and urlsplit() for more information on the result
object.
New in version 2.2.
Changed in version 2.5: Added attributes to return value.
-
urlparse.urlunsplit(parts)
Combine the elements of a tuple as returned by urlsplit() into a complete
URL as a string. The parts argument can be any five-item iterable. This may
result in a slightly different, but equivalent URL, if the URL that was parsed
originally had unnecessary delimiters (for example, a ? with an empty query; the
RFC states that these are equivalent).
New in version 2.2.
-
urlparse.urljoin(base, url[, allow_fragments])
Construct a full (“absolute”) URL by combining a “base URL” (base) with
another 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. For example:
>>> from urlparse import urljoin
>>> urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')
'http://www.cwi.nl/%7Eguido/FAQ.html'
The allow_fragments argument has the same meaning and default as for
urlparse().
Note
If url is an absolute URL (that is, starting with // or scheme://),
the url‘s host name and/or scheme will be present in the result. For example:
>>> urljoin('http://www.cwi.nl/%7Eguido/Python.html',
... '//www.python.org/%7Eguido')
'http://www.python.org/%7Eguido'
If you do not want that behavior, preprocess the url with urlsplit() and
urlunsplit(), removing possible scheme and netloc parts.
-
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.
See also
- RFC 1738 - Uniform Resource Locators (URL)
- This specifies the formal syntax and semantics of absolute URLs.
- RFC 1808 - Relative Uniform Resource Locators
- This Request For Comments includes the rules for joining an absolute and a
relative URL, including a fair number of “Abnormal Examples” which govern the
treatment of border cases.
- RFC 2396 - Uniform Resource Identifiers (URI): Generic Syntax
- Document describing the generic syntactic requirements for both Uniform Resource
Names (URNs) and Uniform Resource Locators (URLs).
The result objects from the urlparse() and urlsplit() functions are
subclasses of the tuple type. These subclasses add the attributes
described in those functions, as well as provide an additional method:
-
ParseResult.geturl()
Return the re-combined version of the original URL as a string. This may differ
from the original URL in that the scheme will always be normalized to lower case
and empty components may be dropped. Specifically, empty parameters, queries,
and fragment identifiers will be removed.
The result of this method is a fixpoint if passed back through the original
parsing function:
>>> import urlparse
>>> url = 'HTTP://www.Python.org/doc/#'
>>> r1 = urlparse.urlsplit(url)
>>> r1.geturl()
'http://www.Python.org/doc/'
>>> r2 = urlparse.urlsplit(r1.geturl())
>>> r2.geturl()
'http://www.Python.org/doc/'
New in version 2.5.
The following classes provide the implementations of the parse results:
.. class:: BaseResult
Base class for the concrete result classes. This provides most of the attribute
definitions. It does not provide a geturl() method. It is derived from
tuple, but does not override the __init__() or __new__()
methods.
-
class urlparse.ParseResult(scheme, netloc, path, params, query, fragment)
- Concrete class for urlparse() results. The __new__() method is
overridden to support checking that the right number of arguments are passed.
-
class urlparse.SplitResult(scheme, netloc, path, query, fragment)
- Concrete class for urlsplit() results. The __new__() method is
overridden to support checking that the right number of arguments are passed.
|