Doc/library/urllib.parse.rst - platform/external/python/cpython3 - Gitiles

 :mod:`urllib.parse` --- Parse URLs into components
 ==================================================

 .. module:: urllib.parse
    :synopsis: Parse URLs into or assemble them from components.


 .. index::
    single: WWW
    single: World Wide Web
    single: URL
    pair: URL; parsing
    pair: relative; URL

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

 .. function:: urlparse(urlstring, scheme='', allow_fragments=True)

    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 *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 :const:`True`.

    The return value is actually an instance of a subclass of :class:`tuple`.  This
    class has the following additional read-only convenience attributes:

    +------------------+-------+--------------------------+----------------------+
    | Attribute        | Index | Value                    | Value if not present |
    +==================+=======+==========================+======================+
    | :attr:`scheme`   | 0     | URL scheme specifier     | empty string         |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`netloc`   | 1     | Network location part    | empty string         |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`path`     | 2     | Hierarchical path        | empty string         |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`params`   | 3     | Parameters for last path | empty string         |
    |                  |       | element                  |                      |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`query`    | 4     | Query component          | empty string         |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`fragment` | 5     | Fragment identifier      | empty string         |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`username` |       | User name                | :const:`None`        |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`password` |       | Password                 | :const:`None`        |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`hostname` |       | Host name (lower case)   | :const:`None`        |
    +------------------+-------+--------------------------+----------------------+
    | :attr:`port`     |       | Port number as integer,  | :const:`None`        |
    |                  |       | if present               |                      |
    +------------------+-------+--------------------------+----------------------+

    See section :ref:`urlparse-result-object` for more information on the result
    object.

    .. versionchanged:: 3.2
       Added IPv6 URL parsing capabilities.


 .. function:: parse_qs(qs, keep_blank_values=False, strict_parsing=False)

    Parse a query string given as a string argument (data of type
    :mimetype:`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 :exc:`ValueError` exception.

    Use the :func:`urllib.parse.urlencode` function to convert such
    dictionaries into query strings.


 .. function:: parse_qsl(qs, keep_blank_values=False, strict_parsing=False)

    Parse a query string given as a string argument (data of type
    :mimetype:`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 :exc:`ValueError` exception.

    Use the :func:`urllib.parse.urlencode` function to convert such lists of pairs into
    query strings.


 .. function:: 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).


 .. function:: urlsplit(urlstring, scheme='', allow_fragments=True)

    This is similar to :func:`urlparse`, but does not split the params from the URL.
    This should generally be used instead of :func:`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 :class:`tuple`.  This
    class has the following additional read-only convenience attributes:

    +------------------+-------+-------------------------+----------------------+
    | Attribute        | Index | Value                   | Value if not present |
    +==================+=======+=========================+======================+
    | :attr:`scheme`   | 0     | URL scheme specifier    | empty string         |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`netloc`   | 1     | Network location part   | empty string         |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`path`     | 2     | Hierarchical path       | empty string         |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`query`    | 3     | Query component         | empty string         |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`fragment` | 4     | Fragment identifier     | empty string         |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`username` |       | User name               | :const:`None`        |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`password` |       | Password                | :const:`None`        |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`hostname` |       | Host name (lower case)  | :const:`None`        |
    +------------------+-------+-------------------------+----------------------+
    | :attr:`port`     |       | Port number as integer, | :const:`None`        |
    |                  |       | if present              |                      |
    +------------------+-------+-------------------------+----------------------+

    See section :ref:`urlparse-result-object` for more information on the result
    object.


 .. function:: urlunsplit(parts)

    Combine the elements of a tuple as returned by :func:`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).


 .. function:: urljoin(base, url, allow_fragments=True)

    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
    :func:`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:

    .. doctest::

       >>> 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 :func:`urlsplit` and
    :func:`urlunsplit`, removing possible *scheme* and *netloc* parts.


 .. function:: 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.


 .. function:: quote(string, safe='/', encoding=None, errors=None)

    Replace special characters in *string* using the ``%xx`` escape. Letters,
    digits, and the characters ``'_.-'`` are never quoted. By default, this
    function is intended for quoting the path section of URL. The optional *safe*
    parameter specifies additional ASCII characters that should not be quoted
    --- its default value is ``'/'``.

    *string* may be either a :class:`str` or a :class:`bytes`.

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


 .. function:: quote_plus(string, safe='', encoding=None, errors=None)

    Like :func:`quote`, but also replace spaces by plus signs, as required for
    quoting HTML form values when building up a query string to go into a URL.
    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'``.


 .. function:: quote_from_bytes(bytes, safe='/')

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

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


 .. function:: unquote(string, encoding='utf-8', errors='replace')

    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
    :meth:`bytes.decode` method.

    *string* must be a :class:`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/'``.


 .. function:: unquote_plus(string, encoding='utf-8', errors='replace')

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

    *string* must be a :class:`str`.

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


 .. function:: unquote_to_bytes(string)

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

    *string* may be either a :class:`str` or a :class:`bytes`.

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

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


 .. function:: urlencode(query, doseq=False, safe='', encoding=None, errors=None)

    Convert a mapping object or a sequence of two-element tuples, which may
    either be a :class:`str` or a :class:`bytes`,  to a "url-encoded" string,
    suitable to pass to :func:`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 :func:`quote_plus`
    above. 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 value element in itself can be a sequence and in that case, if
    the optional parameter *doseq* is evaluates to *True*, individual
    ``key=value`` pairs separated by ``'&'`` are generated for each element of
    the value sequence for the key.  The order of parameters in the encoded
    string will match the order of parameter tuples in the sequence. This module
    provides the functions :func:`parse_qs` and :func:`parse_qsl` which are used
    to parse query strings into Python data structures.

    When *query* parameter is a :class:`str`, the *safe*, *encoding* and *error*
    parameters are sent the :func:`quote_plus` for encoding.

    .. versionchanged:: 3.2
       query paramater supports bytes and string.


 .. seealso::

    :rfc:`3986` - Uniform Resource Identifiers
       This is the current standard (STD66). Any changes to urlparse module
       should conform to this. Certain deviations could be observed, which are
       mostly due backward compatiblity purposes and for certain de-facto
       parsing requirements as commonly observed in major browsers.

    :rfc:`2732` - Format for Literal IPv6 Addresses in URL's.
       This specifies the parsing requirements of IPv6 URLs.

    :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).

    :rfc:`2368` - The mailto URL scheme.
       Parsing requirements for mailto url schemes.

    :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:`1738` - Uniform Resource Locators (URL)
       This specifies the formal syntax and semantics of absolute URLs.


 .. _urlparse-result-object:

 Results of :func:`urlparse` and :func:`urlsplit`
 ------------------------------------------------

 The result objects from the :func:`urlparse` and :func:`urlsplit` functions are
 subclasses of the :class:`tuple` type.  These subclasses add the attributes
 described in those functions, as well as provide an additional method:

 .. 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:: BaseResult

    Base class for the concrete result classes.  This provides most of the
    attribute definitions.  It does not provide a :meth:`geturl` method.  It is
    derived from :class:`tuple`, but does not override the :meth:`__init__` or
    :meth:`__new__` methods.


 .. class:: ParseResult(scheme, netloc, path, params, query, fragment)

    Concrete class for :func:`urlparse` results.  The :meth:`__new__` method is
    overridden to support checking that the right number of arguments are passed.


 .. class:: SplitResult(scheme, netloc, path, query, fragment)

    Concrete class for :func:`urlsplit` results.  The :meth:`__new__` method is
    overridden to support checking that the right number of arguments are passed.
	:mod:`urllib.parse` --- Parse URLs into components
	==================================================

	.. module:: urllib.parse
	:synopsis: Parse URLs into or assemble them from components.


	.. index::
	single: WWW
	single: World Wide Web
	single: URL
	pair: URL; parsing
	pair: relative; URL

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

	.. function:: urlparse(urlstring, scheme='', allow_fragments=True)

	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 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 :const:`True`.

	The return value is actually an instance of a subclass of :class:`tuple`. This
	class has the following additional read-only convenience attributes:

	+------------------+-------+--------------------------+----------------------+
	\| Attribute \| Index \| Value \| Value if not present \|
	+==================+=======+==========================+======================+
	\| :attr:`scheme` \| 0 \| URL scheme specifier \| empty string \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`netloc` \| 1 \| Network location part \| empty string \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`path` \| 2 \| Hierarchical path \| empty string \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`params` \| 3 \| Parameters for last path \| empty string \|
	\| \| \| element \| \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`query` \| 4 \| Query component \| empty string \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`fragment` \| 5 \| Fragment identifier \| empty string \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`username` \| \| User name \| :const:`None` \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`password` \| \| Password \| :const:`None` \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`hostname` \| \| Host name (lower case) \| :const:`None` \|
	+------------------+-------+--------------------------+----------------------+
	\| :attr:`port` \| \| Port number as integer, \| :const:`None` \|
	\| \| \| if present \| \|
	+------------------+-------+--------------------------+----------------------+

	See section :ref:`urlparse-result-object` for more information on the result
	object.

	.. versionchanged:: 3.2
	Added IPv6 URL parsing capabilities.


	.. function:: parse_qs(qs, keep_blank_values=False, strict_parsing=False)

	Parse a query string given as a string argument (data of type
	:mimetype:`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 :exc:`ValueError` exception.

	Use the :func:`urllib.parse.urlencode` function to convert such
	dictionaries into query strings.


	.. function:: parse_qsl(qs, keep_blank_values=False, strict_parsing=False)

	Parse a query string given as a string argument (data of type
	:mimetype:`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 :exc:`ValueError` exception.

	Use the :func:`urllib.parse.urlencode` function to convert such lists of pairs into
	query strings.


	.. function:: 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).


	.. function:: urlsplit(urlstring, scheme='', allow_fragments=True)

	This is similar to :func:`urlparse`, but does not split the params from the URL.
	This should generally be used instead of :func:`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 :class:`tuple`. This
	class has the following additional read-only convenience attributes:

	+------------------+-------+-------------------------+----------------------+
	\| Attribute \| Index \| Value \| Value if not present \|
	+==================+=======+=========================+======================+
	\| :attr:`scheme` \| 0 \| URL scheme specifier \| empty string \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`netloc` \| 1 \| Network location part \| empty string \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`path` \| 2 \| Hierarchical path \| empty string \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`query` \| 3 \| Query component \| empty string \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`fragment` \| 4 \| Fragment identifier \| empty string \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`username` \| \| User name \| :const:`None` \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`password` \| \| Password \| :const:`None` \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`hostname` \| \| Host name (lower case) \| :const:`None` \|
	+------------------+-------+-------------------------+----------------------+
	\| :attr:`port` \| \| Port number as integer, \| :const:`None` \|
	\| \| \| if present \| \|
	+------------------+-------+-------------------------+----------------------+

	See section :ref:`urlparse-result-object` for more information on the result
	object.


	.. function:: urlunsplit(parts)

	Combine the elements of a tuple as returned by :func:`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).


	.. function:: urljoin(base, url, allow_fragments=True)

	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
	:func:`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:

	.. doctest::

	>>> 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 :func:`urlsplit` and
	:func:`urlunsplit`, removing possible scheme and netloc parts.


	.. function:: 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.


	.. function:: quote(string, safe='/', encoding=None, errors=None)

	Replace special characters in string using the ``%xx`` escape. Letters,
	digits, and the characters ``'_.-'`` are never quoted. By default, this
	function is intended for quoting the path section of URL. The optional safe
	parameter specifies additional ASCII characters that should not be quoted
	--- its default value is ``'/'``.

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

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


	.. function:: quote_plus(string, safe='', encoding=None, errors=None)

	Like :func:`quote`, but also replace spaces by plus signs, as required for
	quoting HTML form values when building up a query string to go into a URL.
	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'``.


	.. function:: quote_from_bytes(bytes, safe='/')

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

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


	.. function:: unquote(string, encoding='utf-8', errors='replace')

	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
	:meth:`bytes.decode` method.

	string must be a :class:`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/'``.


	.. function:: unquote_plus(string, encoding='utf-8', errors='replace')

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

	string must be a :class:`str`.

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


	.. function:: unquote_to_bytes(string)

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

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

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

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


	.. function:: urlencode(query, doseq=False, safe='', encoding=None, errors=None)

	Convert a mapping object or a sequence of two-element tuples, which may
	either be a :class:`str` or a :class:`bytes`, to a "url-encoded" string,
	suitable to pass to :func:`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 :func:`quote_plus`
	above. 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 value element in itself can be a sequence and in that case, if
	the optional parameter doseq is evaluates to True, individual
	``key=value`` pairs separated by ``'&'`` are generated for each element of
	the value sequence for the key. The order of parameters in the encoded
	string will match the order of parameter tuples in the sequence. This module
	provides the functions :func:`parse_qs` and :func:`parse_qsl` which are used
	to parse query strings into Python data structures.

	When query parameter is a :class:`str`, the safe, encoding and error
	parameters are sent the :func:`quote_plus` for encoding.

	.. versionchanged:: 3.2
	query paramater supports bytes and string.


	.. seealso::

	:rfc:`3986` - Uniform Resource Identifiers
	This is the current standard (STD66). Any changes to urlparse module
	should conform to this. Certain deviations could be observed, which are
	mostly due backward compatiblity purposes and for certain de-facto
	parsing requirements as commonly observed in major browsers.

	:rfc:`2732` - Format for Literal IPv6 Addresses in URL's.
	This specifies the parsing requirements of IPv6 URLs.

	: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).

	:rfc:`2368` - The mailto URL scheme.
	Parsing requirements for mailto url schemes.

	: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:`1738` - Uniform Resource Locators (URL)
	This specifies the formal syntax and semantics of absolute URLs.


	.. _urlparse-result-object:

	Results of :func:`urlparse` and :func:`urlsplit`
	------------------------------------------------

	The result objects from the :func:`urlparse` and :func:`urlsplit` functions are
	subclasses of the :class:`tuple` type. These subclasses add the attributes
	described in those functions, as well as provide an additional method:

	.. 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:: BaseResult

	Base class for the concrete result classes. This provides most of the
	attribute definitions. It does not provide a :meth:`geturl` method. It is
	derived from :class:`tuple`, but does not override the :meth:`__init__` or
	:meth:`__new__` methods.


	.. class:: ParseResult(scheme, netloc, path, params, query, fragment)

	Concrete class for :func:`urlparse` results. The :meth:`__new__` method is
	overridden to support checking that the right number of arguments are passed.


	.. class:: SplitResult(scheme, netloc, path, query, fragment)

	Concrete class for :func:`urlsplit` results. The :meth:`__new__` method is
	overridden to support checking that the right number of arguments are passed.