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python-3.7.4-docs-html/_sources/library/urllib.robotparser.rst.txt

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+: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 <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 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