Compute entropy of a probability vector

entropy.py

import math

def entropy(vec):
    norm = sum(vec)
    p = (x / norm for x in vec)
    return -sum(p_k * math.log(p_k) for p_k in p if p_k)

import numpy as np

def entropy(p):
    p = np.array(p)
    p /= sum(p)
    return -sum(p * np.log(p))