Get Class Methods with Python

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As a newbie to the excellent world of Python development, I'm not always familiar with the methods provided by imported classes.  Oftentimes these classes are well-documented but in the case that methods aren't documented, I found the dir function useful for getting a list of methods:

# dir({object})
dir(difflib)

"""
Returns:

['Differ', 'HtmlDiff', 'IS_CHARACTER_JUNK', 'IS_LINE_JUNK', 'Match', 'SequenceMatcher', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '_calculate_ratio', '_count_leading', '_file_template', '_legend', '_mdiff', '_namedtuple', '_styles', '_table_template', '_test', 'context_diff', 'get_close_matches', 'heapq', 'ndiff', 'reduce', 'restore', 'unified_diff']

"""

The snippet above does exactly what you would expect -- provides a list of method names for the viewing!

Raygun Pulse

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Discussion

  1. hwiechers

    Isn’t this normall done with dir(difflib)?

    • That does the same thing but alphabetizes the result. Thanks for mentioning that!

  2. Jasper

    It does not do the same thing. dir(my_object) will show you everything you can do on the instance, including methods on the class, and superclasses. __dict__ will only show you the unique things that belong to the object, which isn’t very many.

    • Thanks for the additional information Jasper! I’ve updated my post!

  3. Marcin

    You can also use bpython shell which is a nice alternative to ipython and standard python ones. It has auto-completion which displays all available methods and attributes on any object. It can be installed in virtualenv with pip install bpython.

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