urllib.robotparser —  Parser for robots.txt¶
Source code: Lib/urllib/robotparser.py
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://www.robotstxt.org/orig.html.
- 
class urllib.robotparser.RobotFileParser(url='')¶
- This class provides methods to read, parse and answer questions about the - robots.txtfile at url.- 
set_url(url)¶
- Sets the URL referring to a - robots.txtfile.
 - 
read()¶
- Reads the - robots.txtURL and feeds it to the parser.
 - 
parse(lines)¶
- Parses the lines argument. 
 - 
can_fetch(useragent, url)¶
- Returns - Trueif the useragent is allowed to fetch the url according to the rules contained in the parsed- robots.txtfile.
 - 
mtime()¶
- Returns the time the - robots.txtfile was last fetched. This is useful for long-running web spiders that need to check for new- robots.txtfiles periodically.
 - 
modified()¶
- Sets the time the - robots.txtfile was last fetched to the current time.
 - 
crawl_delay(useragent)¶
- Returns the value of the - Crawl-delayparameter from- robots.txtfor the useragent in question. If there is no such parameter or it doesn’t apply to the useragent specified or the- robots.txtentry for this parameter has invalid syntax, return- None.- New in version 3.6. 
 - 
request_rate(useragent)¶
- Returns the contents of the - Request-rateparameter from- robots.txtas a named tuple- RequestRate(requests, seconds). If there is no such parameter or it doesn’t apply to the useragent specified or the- robots.txtentry for this parameter has invalid syntax, return- None.- New in version 3.6. 
 
- 
The following example demonstrates basic use of the 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