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pythonunit-testingmockingpython-unittestpython-mock

How to create a subscriptable Mock object?


Suppose, I have a code snippet as

foo = SomeClass()
bar = foo[1:999].execute()

To test this, I have tried something as

foo_mock = Mock()
foo_mock[1:999].execute()

Unfortunately, this raised an exception,

TypeError: 'Mock' object is not subscriptable

So, How can I create a subscriptable Mock object?


Solution

  • Just use a MagicMock instead.

    >>> from unittest.mock import Mock, MagicMock
    >>> Mock()[1:999]
    TypeError: 'Mock' object is not subscriptable
    >>> MagicMock()[1:999]
    <MagicMock name='mock.__getitem__()' id='140737078563504'>
    

    It's so called "magic" because it supports __magic__ methods such as __getitem__.