comparing numpy arrays containing NaN

Question

For my unittest, I want to check if two arrays are identical. Reduced example:

a = np.array([1, 2, np.NaN])
b = np.array([1, 2, np.NaN])
if np.all(a==b):
          


        

Answer 1

If you do this for things like unit tests, so you don't care much about performance and "correct" behaviour with all types, you can use this to have something that works with all types of arrays, not just numeric:

a = np.array(['a', 'b', None])
b = np.array(['a', 'b', None])
assert list(a) == list(b)

Casting ndarrays to lists can sometimes be useful to get the behaviour you want in some test. (But don't use this in production code, or with larger arrays!)