Method assertApproxEqual

Lib/test/test_statistics.py:217–259

Test passes if ``first`` and ``second`` are approximately equal. This test passes if ``first`` and ``second`` are equal to within ``tol``, an absolute error, or ``rel``, a relative error. If either ``tol`` or ``rel`` are None or not given, they default to test attri

(
            self, first, second, tol=None, rel=None, msg=None
            )

    tol = rel = 0

    def assertApproxEqual(
            self, first, second, tol=None, rel=None, msg=None
            ):
        """Test passes if ``first`` and ``second`` are approximately equal.

        This test passes if ``first`` and ``second`` are equal to
        within ``tol``, an absolute error, or ``rel``, a relative error.

        If either ``tol`` or ``rel`` are None or not given, they default to
        test attributes of the same name (by default, 0).

        The objects may be either numbers, or sequences of numbers. Sequences
        are tested element-by-element.

        >>> class MyTest(NumericTestCase):
        ...     def test_number(self):
        ...         x = 1.0/6
        ...         y = sum([x]*6)
        ...         self.assertApproxEqual(y, 1.0, tol=1e-15)
        ...     def test_sequence(self):
        ...         a = [1.001, 1.001e-10, 1.001e10]
        ...         b = [1.0, 1e-10, 1e10]
        ...         self.assertApproxEqual(a, b, rel=1e-3)
        ...
        >>> import unittest
        >>> from io import StringIO  # Suppress test runner output.
        >>> suite = unittest.TestLoader().loadTestsFromTestCase(MyTest)
        >>> unittest.TextTestRunner(stream=StringIO()).run(suite)
        <unittest.runner.TextTestResult run=2 errors=0 failures=0>

        """
        if tol is None:
            tol = self.tol
        if rel is None:
            rel = self.rel
        if (
                isinstance(first, collections.abc.Sequence) and
                isinstance(second, collections.abc.Sequence)
            ):
            check = self._check_approx_seq
        else:
            check = self._check_approx_num
        check(first, second, tol, rel, msg)

    def _check_approx_seq(self, first, second, tol, rel, msg):
        if len(first) != len(second):