How to use numpy with 'None' value in Python?

Question

I\'d like to calculate the mean of an array in Python in this form:

Matrice = [1, 2, None]

I\'d just like to have my None valu

Answer 1

You can 'upcast' the array to numpy's float64 dtype and then use numpy's nanmean method as in the following example:

import numpy as np

arr = [1,2,3, None]
arr2 = np.array(arr, dtype=np.float64)
print(arr2) # [ 1.  2.  3. nan]
print(np.nanmean(arr2)) # 2.0