symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/robotparser.rst
author johnathan.white@2718R8BGH51.accenture.com
Mon, 08 Mar 2010 18:45:03 +0000
changeset 46 b6935a90ca64
parent 1 2fb8b9db1c86
permissions -rw-r--r--
Modify framebuffer and NGA framebuffer to read screen size from board model dtb file. Optimise memory usuage of frame buffer Add example minigui application with hooks to profiler (which writes results to S:\). Modified NGA framebuffer to run its own dfc queue at high priority


:mod:`robotparser` ---  Parser for robots.txt
=============================================

.. module:: robotparser
   :synopsis: Loads a robots.txt file and answers questions about
              fetchability of other URLs.
.. sectionauthor:: Skip Montanaro <skip@pobox.com>


.. index::
   single: WWW
   single: World Wide Web
   single: URL
   single: robots.txt
   
.. note::
   The :mod:`robotparser` module has been renamed :mod:`urllib.robotparser` in
   Python 3.0.
   The :term:`2to3` tool will automatically adapt imports when converting
   your sources to 3.0.

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()

   This class provides a set of methods to read, parse and answer questions
   about a single :file:`robots.txt` file.


   .. 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.

The following example demonstrates basic use of the RobotFileParser class. ::

   >>> import robotparser
   >>> rp = robotparser.RobotFileParser()
   >>> rp.set_url("http://www.musi-cal.com/robots.txt")
   >>> rp.read()
   >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco")
   False
   >>> rp.can_fetch("*", "http://www.musi-cal.com/")
   True