1 :mod:`urllib.robotparser` --- Parser for robots.txt 2 ==================================================== 3 4 .. module:: urllib.robotparser 5 :synopsis: Load a robots.txt file and answer questions about 6 fetchability of other URLs. 7 8 .. sectionauthor:: Skip Montanaro <skip (a] pobox.com> 9 10 **Source code:** :source:`Lib/urllib/robotparser.py` 11 12 .. index:: 13 single: WWW 14 single: World Wide Web 15 single: URL 16 single: robots.txt 17 18 -------------- 19 20 This module provides a single class, :class:`RobotFileParser`, which answers 21 questions about whether or not a particular user agent can fetch a URL on the 22 Web site that published the :file:`robots.txt` file. For more details on the 23 structure of :file:`robots.txt` files, see http://www.robotstxt.org/orig.html. 24 25 26 .. class:: RobotFileParser(url='') 27 28 This class provides methods to read, parse and answer questions about the 29 :file:`robots.txt` file at *url*. 30 31 .. method:: set_url(url) 32 33 Sets the URL referring to a :file:`robots.txt` file. 34 35 .. method:: read() 36 37 Reads the :file:`robots.txt` URL and feeds it to the parser. 38 39 .. method:: parse(lines) 40 41 Parses the lines argument. 42 43 .. method:: can_fetch(useragent, url) 44 45 Returns ``True`` if the *useragent* is allowed to fetch the *url* 46 according to the rules contained in the parsed :file:`robots.txt` 47 file. 48 49 .. method:: mtime() 50 51 Returns the time the ``robots.txt`` file was last fetched. This is 52 useful for long-running web spiders that need to check for new 53 ``robots.txt`` files periodically. 54 55 .. method:: modified() 56 57 Sets the time the ``robots.txt`` file was last fetched to the current 58 time. 59 60 .. method:: crawl_delay(useragent) 61 62 Returns the value of the ``Crawl-delay`` parameter from ``robots.txt`` 63 for the *useragent* in question. If there is no such parameter or it 64 doesn't apply to the *useragent* specified or the ``robots.txt`` entry 65 for this parameter has invalid syntax, return ``None``. 66 67 .. versionadded:: 3.6 68 69 .. method:: request_rate(useragent) 70 71 Returns the contents of the ``Request-rate`` parameter from 72 ``robots.txt`` in the form of a :func:`~collections.namedtuple` 73 ``(requests, seconds)``. If there is no such parameter or it doesn't 74 apply to the *useragent* specified or the ``robots.txt`` entry for this 75 parameter has invalid syntax, return ``None``. 76 77 .. versionadded:: 3.6 78 79 80 The following example demonstrates basic use of the :class:`RobotFileParser` 81 class:: 82 83 >>> import urllib.robotparser 84 >>> rp = urllib.robotparser.RobotFileParser() 85 >>> rp.set_url("http://www.musi-cal.com/robots.txt") 86 >>> rp.read() 87 >>> rrate = rp.request_rate("*") 88 >>> rrate.requests 89 3 90 >>> rrate.seconds 91 20 92 >>> rp.crawl_delay("*") 93 6 94 >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco") 95 False 96 >>> rp.can_fetch("*", "http://www.musi-cal.com/") 97 True 98
