Compare (assert equality of) two complex data structures containing numpy arrays in unittest

Question

I use Python\'s unittest module and want to check if two complex data structures are equal. The objects can be lists of dicts with all sorts of values: numbers,

Answer 1

The assertEqual function will invoke the __eq__ method of objects, which should recurse for complex data types. The exception is numpy, which doesn't have a sane __eq__ method. Using a numpy subclass from this question, you can restore sanity to the equality behavior:

import copy
import numpy
import unittest

class SaneEqualityArray(numpy.ndarray):
    def __eq__(self, other):
        return (isinstance(other, SaneEqualityArray) and
                self.shape == other.shape and
                numpy.ndarray.__eq__(self, other).all())

class TestAsserts(unittest.TestCase):

    def testAssert(self):
        tests = [
            [1, 2],
            {'foo': 2},
            [2, 'foo', {'d': 4}],
            SaneEqualityArray([1, 2]),
            {'foo': {'hey': SaneEqualityArray([2, 3])}},
            [{'foo': SaneEqualityArray([3, 4]), 'd': {'doo': 3}},
             SaneEqualityArray([5, 6]), 34]
        ]
        for t in tests:
            self.assertEqual(t, copy.deepcopy(t))

if __name__ == '__main__':
    unittest.main()

This test passes.