how to use assert_frame_equal in unittest

alecxe answer is incomplete, you can indeed use pandas' assert_frame_equal() with unittest.TestCase, using unittest.TestCase.addTypeEqualityFunc

import unittest
import pandas as pd
import pandas.testing as pd_testing

class TestSplitWeight(unittest.TestCase):
    def assertDataframeEqual(self, a, b, msg):
        try:
            pd_testing.assert_frame_equal(a, b)
        except AssertionError as e:
            raise self.failureException(msg) from e

    def setUp(self):
        self.addTypeEqualityFunc(pd.DataFrame, self.assertDataframeEqual)

    def test_allZero(self):
        self.assertEqual(pd.DataFrame([0,0,0,0]), pd.DataFrame([0,0,0,0]))

assert_frame_equal() is coming from the pandas.util.testing package, not from the unittest.TestCase class. Replace:

self.assert_frame_equal(pd.DataFrame([0,0,0,0]),pd.DataFrame([0,0,0,0]))

with:

assert_frame_equal(pd.DataFrame([0,0,0,0]), pd.DataFrame([0,0,0,0]))

---

When you had self.assert_frame_equal, it tried to find assert_frame_equal attribute on the unittest.TestCase instance, and, since there is not assert_frame_equal attribute or method exposed on an unittest.TestCase class, it raised an AttributeError.