# 12.18 `robotparser` -- Parser for robots.txt

This module provides a single class, `RobotFileParser`, which answers questions about whether or not a particular user agent can fetch a URL on the web site that published the robots.txt file. For more details on the structure of robots.txt files, see http://info.webcrawler.com/mak/projects/robots/norobots.html .

`RobotFileParser` ()

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

  `set_url` (url)
    Sets the URL referring to a robots.txt file.

  `read` ()
    Reads the robots.txt URL and feeds it to the parser.

  `parse` (lines)
    Parses the lines argument.

  `can_fetch` (useragent, url)
    Returns true if the useragent is allowed to fetch the url according to the rules contained in the parsed robots.txt file.

  `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.

  `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")
      0
      >>> rp.can_fetch("*", "http://www.musi-cal.com/")
      1