assertNotAlmostEqual

assertNotAlmostEqual is a test assertion method provided by the Python unittest framework that verifies two numeric values are not close to each other within a specified tolerance. It is used to assert that the difference between two numbers exceeds a threshold, rather than being within an acceptable range. The method is defined in the TestCase class:

```python

def assertNotAlmostEqual(self, first, second, places=7, msg=None, delta=None)

```

The first two positional arguments are the values to compare. The optional `places` argument specifies the number of decimal places to use when comparing the values, and it is used only if `delta` is not supplied. The `delta` argument, if provided, sets an absolute tolerance for the comparison. If neither `places` nor `delta` are specified, the default tolerance is 10⁻⁷. The `msg` argument allows a custom message to be supplied if the assertion fails.

When the absolute difference between `first` and `second` is less than or equal to the calculated tolerance, the assertion fails and an AssertionError is raised. Conversely, if the difference exceeds the tolerance, the test passes. If `places` is used, the difference is rounded to that many decimal places before comparison.

Typical usage:

```python

self.assertNotAlmostEqual(0.123456, 0.123457, places=5) # passes, diff is 0.000001 > 10⁻⁵

self.assertNotAlmostEqual(1.0, 1.0 + 1e-8, delta=1e-7) # fails

```

This assertion is useful when verifying that two results are significantly distinct, such as testing that a transformation or computation has altered a value by more than a negligible amount. It is part of the same family of almost-equal assertions—including assertAlmostEqual and assertAlmostEquals—that provide flexible numeric comparison in unit tests.