“OverflowError: Python int too large to convert to C long” on windows but not mac

I think you are getting overflowerror: python int too large to convert to c long error message because your numbers are greater than sys.maxsize:

>>> p = [sys.maxsize]

>>> preds[0] = p

>>> p = [sys.maxsize+1]

>>> preds[0] = p

Traceback (most recent call last):

  File "", line 1, in 

OverflowError: Python int too large to convert to C long

You can check this with the below code:

>>> import sys

>>> sys.maxsize

2147483647

To execute the numbers with larger precision, I would suggest you do not pass any int type which uses as bounded C integer behind the scenes. Use the default float:

  >>> preds = np.zeros((1, 3))