Time for action – asserting approximately equal

Let's take the numbers from the previous Time for action section and let the assert_approx_equal() function work on them:

1. Call the function with low significance:

   print("Significance 8", np.testing.assert_approx_equal (0.123456789, 0.123456780,significant=8))

   The result is as follows:

   Significance 8 None
   

2. Call the function with high significance:

   print("Significance 9", np.testing.assert_approx_equal (0.123456789, 0.123456780, significant=9))

   The function raises an AssertionError:

   Significance 9
   Traceback (most recent call last):
     ...
       raise AssertionError(msg)
   AssertionError:
   Items are not equal to 9 significant digits:
    ACTUAL: 0.123456789
    DESIRED: 0.12345678
   

What just happened?

We used the assert_approx_equal() function from the NumPy testing package to check whether 0.123456789 and 0.123456780 are equal for different decimal precisions.