python numpy高效体现

import numpy as np
import time
def python_sum(n):
    a=[i**2 for i in range(n)]
    b=[i**3 for i in range(n)]
    c=[]
    for i in range(n):
        c.append(a[i]+b[i])
    return c
def numpy_sum(n):
    a=np.arange(n)**2
    b=np.arange(n)**3
    return a+b
start=time.time()
python_sum(1000000)
end=time.time()
print(‘python‘,end-start)
start=time.time()
numpy_sum(1000000)
end=time.time()
print(‘numpy‘,end-start)