如何在python中向量化以下四个for循环？

import numpy as np

# 原始的四个for循环
a = [1, 2, 3, 4, 5]
b = [6, 7, 8, 9, 10]
c = [11, 12, 13, 14, 15]
d = [16, 17, 18, 19, 20]

result = []
for i in range(len(a)):
    result.append(a[i] + b[i] + c[i] + d[i])

print(result)

# 向量化操作
a = np.array(a)
b = np.array(b)
c = np.array(c)
d = np.array(d)

result = a + b + c + d
print(result)