How do I test dictionary-equality with Python's doctest-package?

Question

I\'m writing a doctest for a function that outputs a dictionary. The doctest looks like

>>> my_function()
{\'this\': \'is\', \'a\': \'dictionary\'}
         


        

Answer 1

You can create an instance of unittest.TestCase class inside your doctests, and use it to compare dictionaries:

def my_function(x):
    """
    >>> from unittest import TestCase
    >>> t = TestCase()

    >>> t.assertDictEqual(
    ...     my_function('a'),
    ...     {'this': 'is', 'a': 'dictionary'}
    ... )

    >>> t.assertDictEqual(
    ...     my_function('b'),
    ...     {'this': 'is', 'b': 'dictionary'}
    ... )

    """
    return {'this': 'is', x: 'dictionary'}

Note: this approach is better than simply checking if dictionaries are equal, because it will show diff between the two dictionaries.