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# 20.7. `urllib.parse` — 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`, `sftp`, `shttp`, `sip`, `sips`, `snews`, `svn`, `svn+ssh`, `telnet`, `wais`.

The `urllib.parse` module defines the following functions:

`urllib.parse.``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 urllib.parse 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.

`urllib.parse.``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.parse.urlencode()` function to convert such dictionaries into query strings.

`urllib.parse.``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.parse.urlencode()` function to convert such lists of pairs into query strings.

`urllib.parse.``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).

`urllib.parse.``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.

`urllib.parse.``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).

`urllib.parse.``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 urllib.parse 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.

`urllib.parse.``urldefrag`(url)
  If url contains a fragment identifier, return 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, return url unmodified and an empty string.

`urllib.parse.``quote`(string[, safe[, encoding[, errors]]])

  Replace special characters in string using the `%xx` escape. Letters, digits, and the characters `'_.-'` are never quoted. The optional safe parameter specifies additional ASCII characters that should not be quoted — its default value is `'/'`.

  string may be either a `str` or a `bytes`.

  The optional encoding and errors parameters specify how to deal with non-ASCII characters, as accepted by the `str.encode()` method. encoding defaults to `'utf-8'`. errors defaults to `'strict'`, meaning unsupported characters raise a `UnicodeEncodeError`. encoding and errors must not be supplied if string is a `bytes`, or a `TypeError` is raised.

  Note that `quote(string, safe, encoding, errors)` is equivalent to `quote_from_bytes(string.encode(encoding, errors), safe)`.

  Example: `quote('/El Niño/')` yields `'/El%20Ni%C3%B1o/'`.

`urllib.parse.``quote_plus`(string[, safe[, encoding[, errors]]])

  Like `quote()`, but also replace spaces by plus signs, as required for quoting HTML form values. Plus signs in the original string are escaped unless they are included in safe. It also does not have safe default to `'/'`.

  Example: `quote_plus('/El Niño/')` yields `'%2FEl+Ni%C3%B1o%2F'`.

`urllib.parse.``quote_from_bytes`(bytes[, safe])

  Like `quote()`, but accepts a `bytes` object rather than a `str`, and does not perform string-to-bytes encoding.

  Example: `quote_from_bytes(b'a&\xef')` yields `'a%26%EF'`.

`urllib.parse.``unquote`(string[, encoding[, errors]])

  Replace `%xx` escapes by their single-character equivalent. The optional encoding and errors parameters specify how to decode percent-encoded sequences into Unicode characters, as accepted by the `bytes.decode()` method.

  string must be a `str`.

  encoding defaults to `'utf-8'`. errors defaults to `'replace'`, meaning invalid sequences are replaced by a placeholder character.

  Example: `unquote('/El%20Ni%C3%B1o/')` yields `'/El Niño/'`.

`urllib.parse.``unquote_plus`(string[, encoding[, errors]])

  Like `unquote()`, but also replace plus signs by spaces, as required for unquoting HTML form values.

  string must be a `str`.

  Example: `unquote_plus('/El+Ni%C3%B1o/')` yields `'/El Niño/'`.

`urllib.parse.``unquote_to_bytes`(string)

  Replace `%xx` escapes by their single-octet equivalent, and return a `bytes` object.

  string may be either a `str` or a `bytes`.

  If it is a `str`, unescaped non-ASCII characters in string are encoded into UTF-8 bytes.

  Example: `unquote_to_bytes('a%26%EF')` yields `b'a&\xef'`.

`urllib.parse.``urlencode`(query[, doseq])
  Convert a mapping object or a sequence of two-element tuples to a “url-encoded” string, suitable to pass to `urlopen()` above as the optional data argument. This is useful to pass a dictionary of form fields to a `POST` request. The resulting string is a series of `key=value` pairs separated by `'&'` characters, where both key and value are quoted using `quote_plus()` above. If the optional parameter doseq is present and evaluates to true, individual `key=value` pairs are generated for each element of the sequence. When a sequence of two-element tuples is used as the query argument, the first element of each tuple is a key and the second is a value. The order of parameters in the encoded string will match the order of parameter tuples in the sequence. This module provides the functions `parse_qs()` and `parse_qsl()` which are used to parse query strings into Python data structures.

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).

## 20.7.1. Results of `urlparse()` and `urlsplit()`

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 urllib.parse
  >     >>> url = 'HTTP://www.Python.org/doc/#'

  >     >>> r1 = urllib.parse.urlsplit(url)
  >     >>> r1.geturl()
  >     'http://www.Python.org/doc/'

  >     >>> r2 = urllib.parse.urlsplit(r1.geturl())
  >     >>> r2.geturl()
  >     'http://www.Python.org/doc/'

The following classes provide the implementations of the parse results:

class `urllib.parse.``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 `urllib.parse.``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 `urllib.parse.``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.

### Navigation

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- next |
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- Python v3.1c1 documentation »
- The Python Standard Library »
- 20. Internet Protocols and Support »