I'm trying to find a way to know if a number on a matrix is positive, negative or zero. Below is my code, but I'm wondering if there is a more Pythonic way to write that. Any ideas?

array = np.random.randint(-10,10, size=(10,10))

def function(array):
    case1 = np.where(array < 0, -1, array)
    case2 = np.where(case1 > 0, 1, case1)
    case3 = np.where(case2 == 0, 0, case2)
    return case3


You should choose better functions names, function does not give any indication what the purpose of the function is.

In addition, a docstring comment can be used to give a short description.

But actually there is no need for a custom function because numpy.sign already provides the exact functionality:

Returns an element-wise indication of the sign of a number.


import numpy as np

array = np.random.randint(-10,10, size=(4,4))


[[-1  1  1  1]
 [ 1  1  0  0]
 [ 1  1 -1  1]
 [ 1 -1  1 -1]]
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  • \$\begingroup\$ Yes, that's it! Thanks! \$\endgroup\$ – Connie Jun 28 at 21:15

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