11.7: Debugging

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Python has some simple and rudimentary built-in documentation that can be quite helpful if you need a quick refresher to trigger your memory about the exact name of a particular method. This documentation can be viewed in the Python interpreter in interactive mode.

You can bring up an interactive help system using help().

>>> help()

help> modules

If you know what module you want to use, you can use the dir() command to find the methods in the module as follows:

>>> import re
>>> dir(re)
[.. 'compile', 'copy_reg', 'error', 'escape', 'findall',
'finditer', 'match', 'purge', 'search', 'split', 'sre_compile',
'sre_parse', 'sub', 'subn', 'sys', 'template']

You can also get a small amount of documentation on a particular method using the dir command.

>>> help (re.search)
Help on function search in module re:

search(pattern, string, flags=0)
    Scan through string looking for a match to the pattern, returning
    a match object, or None if no match was found.
>>>

The built-in documentation is not very extensive, but it can be helpful when you are in a hurry or don't have access to a web browser or search engine.