3 维 arrays 上的 IndexError

Question

Noob question, but I can't seem to figure out why this is throwing an error: IndexError: index 4 is out of bounds for axis 2 with size 4

import numpy as np

numP = 4;
P = np.zeros((3,3,numP))
P[:,:,1] = np.array([[0.50, 0.25, 0.25],
                [0.20, 0.55, 0.25],
                [0.20, 0.30, 0.50]])
P[:,:,2] = np.array([[0.70, 0.20, 0.10],
                [0.05, 0.75, 0.20],
                [0.10, 0.20, 0.70]])
P[:,:,3] = np.array([[0.45, 0.35, 0.20],
                [0.20, 0.65, 0.15],
                [0.00, 0.30, 0.70]])
P[:,:,4] = np.array([[0.60, 0.20, 0.20],
                [0.20, 0.60, 0.20],
                [0.05, 0.05, 0.90]])

Answer 1

Python is 0-indexed (as in list[0] refers to the first element in the list, list[1] refers to the second element... etc)

so the last assignment should be P[:,:,3]