After changeset http://hg.python.org/lookup/dbed7cacfb7e, calling the crawl_delay method for a robots.txt files that has a crawl-delay for * useragents always returns None.

Ex:

Python 3.6.0a0 (default:1aae9b6a6929+, Oct  9 2015, 22:08:05)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib.robotparser
>>> parser = urllib.robotparser.RobotFileParser()
>>> parser.set_url('https://www.carthage.edu/robots.txt')
>>> parser.read()
>>> parser.crawl_delay('test_robotparser')
>>> parser.crawl_delay('*')
>>> print(parser.default_entry.delay)
120
>>>

Excerpt from https://www.carthage.edu/robots.txt:

User-agent: *
Crawl-Delay: 120
Disallow: /cgi-bin

I have written a patch that solves this. With patch, output is:

Python 3.6.0a0 (default:1aae9b6a6929+, Oct  9 2015, 22:08:05)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib.robotparser
>>> parser = urllib.robotparser.RobotFileParser()
>>> parser.set_url('https://www.carthage.edu/robots.txt')
>>> parser.read()
>>> parser.crawl_delay('test_robotparser')
120
>>> parser.crawl_delay('*')
120
>>> print(parser.default_entry.delay)
120
>>>

This also applies to the request_rate method.

This fix breaks the unit tests though. I am not sure how to go about checking those as this would be my first contribution to python and an open source project in general.

On further inspection of the tests, it appears that the way in which the tests are written, a test case can only be tested for one useragent at a time. I will attempt to work on the tests so work correctly. Any advice would be much appreciated.

Thanks for the patch Peter(and welcome to Python and open source development). I have a WIP patch to rewrite test_robotparser in a less magic way. So we can ignore test failures for now. I'll take a closer look to your patch.

Ok, for the mean time, I reworked the test so it appears to test correctly and tests passes. There does seem to be some magic, so I do hope I did not overlook anything. Here is the new patch.

I've now updated Lib/test/test_robotparser.py (issue 25497) Peter, do you have time to update your patch? Thanks!

Here's an updated patch.

New changeset d5d910cfd288 by Berker Peksag in branch '3.6':
Issue #25400: RobotFileParser now correctly returns default values for crawl_delay and request_rate
https://hg.python.org/cpython/rev/d5d910cfd288

New changeset 911070065e38 by Berker Peksag in branch 'default':
Issue #25400: Merge from 3.6
https://hg.python.org/cpython/rev/911070065e38