import numpy as np
array1D = [20, 2, 7, 1, 34]
print(np.mean(array1D)) # 12.8
array2D = [[14, 17, 12, 33, 44],
[15, 6, 27, 8, 19],
[23, 2, 54, 1, 4]]
# mean of everything in the array, axis = None
print(np.mean(array2D)) # 18.6
# mean along the axis = 0
print(np.mean(array2D, axis = 0)) # [17.333333, 8.333333, 31, 14, 22.333333]
# mean along the axis = 1
print(np.mean(array2D, axis = 1)) # [24, 15, 16.8]