/Doc/library/robotparser.rst

 1
 2:mod:`robotparser` ---  Parser for robots.txt
 3=============================================
 4
 5.. module:: robotparser
 6   :synopsis: Loads a robots.txt file and answers questions about
 7              fetchability of other URLs.
 8.. sectionauthor:: Skip Montanaro <skip@pobox.com>
 9
10
11.. index::
12   single: WWW
13   single: World Wide Web
14   single: URL
15   single: robots.txt
16
17.. note::
18   The :mod:`robotparser` module has been renamed :mod:`urllib.robotparser` in
19   Python 3.0.
20   The :term:`2to3` tool will automatically adapt imports when converting
21   your sources to 3.0.
22
23This module provides a single class, :class:`RobotFileParser`, which answers
24questions about whether or not a particular user agent can fetch a URL on the
25Web site that published the :file:`robots.txt` file.  For more details on the
26structure of :file:`robots.txt` files, see http://www.robotstxt.org/orig.html.
27
28
29.. class:: RobotFileParser()
30
31   This class provides a set of methods to read, parse and answer questions
32   about a single :file:`robots.txt` file.
33
34
35   .. method:: set_url(url)
36
37      Sets the URL referring to a :file:`robots.txt` file.
38
39
40   .. method:: read()
41
42      Reads the :file:`robots.txt` URL and feeds it to the parser.
43
44
45   .. method:: parse(lines)
46
47      Parses the lines argument.
48
49
50   .. method:: can_fetch(useragent, url)
51
52      Returns ``True`` if the *useragent* is allowed to fetch the *url*
53      according to the rules contained in the parsed :file:`robots.txt`
54      file.
55
56
57   .. method:: mtime()
58
59      Returns the time the ``robots.txt`` file was last fetched.  This is
60      useful for long-running web spiders that need to check for new
61      ``robots.txt`` files periodically.
62
63
64   .. method:: modified()
65
66      Sets the time the ``robots.txt`` file was last fetched to the current
67      time.
68
69The following example demonstrates basic use of the RobotFileParser class. ::
70
71   >>> import robotparser
72   >>> rp = robotparser.RobotFileParser()
73   >>> rp.set_url("http://www.musi-cal.com/robots.txt")
74   >>> rp.read()
75   >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco")
76   False
77   >>> rp.can_fetch("*", "http://www.musi-cal.com/")
78   True
79