:mod:urllib.robotparser --- Parser for robots.txt

.. module:: urllib.robotparser :synopsis: Load a robots.txt file and answer questions about fetchability of other URLs.

.. sectionauthor:: Skip Montanaro [email protected]

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 http://www.robotstxt.org/orig.html.

.. class:: RobotFileParser(url='')

This class provides methods to read, parse and answer questions about the :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

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