.. module:: urllib.robotparser :synopsis: Load a robots.txt file and answer questions about fetchability of other URLs.
.. sectionauthor:: Skip Montanaro <skip@pobox.com>
Source code: :source:`Lib/urllib/robotparser.py`
.. index:: single: WWW single: World Wide Web single: URL single: robots.txt
This module provides a single class, :class:`RobotFileParser`, which answers questions about whether or not a particular user agent can fetch a URL on the Web site that published the :file:`robots.txt` file. For more details on the structure of :file:`robots.txt` files, see :file:`robots.txt` file at url.
.. method:: set_url(url) Sets the URL referring to a :file:`robots.txt` file.
.. method:: read() Reads the :file:`robots.txt` URL and feeds it to the parser.
.. method:: parse(lines) Parses the lines argument.
.. method:: can_fetch(useragent, url) Returns ``True`` if the *useragent* is allowed to fetch the *url* according to the rules contained in the parsed :file:`robots.txt` file.
.. method:: mtime() Returns the time the ``robots.txt`` file was last fetched. This is useful for long-running web spiders that need to check for new ``robots.txt`` files periodically.
.. method:: modified() Sets the time the ``robots.txt`` file was last fetched to the current time.
.. method:: crawl_delay(useragent) Returns the value of the ``Crawl-delay`` parameter from ``robots.txt`` for the *useragent* in question. If there is no such parameter or it doesn't apply to the *useragent* specified or the ``robots.txt`` entry for this parameter has invalid syntax, return ``None``. .. versionadded:: 3.6
.. method:: request_rate(useragent) Returns the contents of the ``Request-rate`` parameter from ``robots.txt`` as a :term:`named tuple` ``RequestRate(requests, seconds)``. If there is no such parameter or it doesn't apply to the *useragent* specified or the ``robots.txt`` entry for this parameter has invalid syntax, return ``None``. .. versionadded:: 3.6
.. method:: site_maps() Returns the contents of the ``Sitemap`` parameter from ``robots.txt`` in the form of a :func:`list`. If there is no such parameter or the ``robots.txt`` entry for this parameter has invalid syntax, return ``None``. .. versionadded:: 3.8
The following example demonstrates basic use of the :class:`RobotFileParser` class:
>>> import urllib.robotparser
>>> rp = urllib.robotparser.RobotFileParser()
>>> rp.set_url("http://www.musi-cal.com/robots.txt")
>>> rp.read()
>>> rrate = rp.request_rate("*")
>>> rrate.requests
3
>>> rrate.seconds
20
>>> rp.crawl_delay("*")
6
>>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco")
False
>>> rp.can_fetch("*", "http://www.musi-cal.com/")
True
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