想弄一弄tensorflow，先弄numpy

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import numpy
import sys
from datetime import datetime

def numpysum(n):
    a = numpy.arange(n) ** 2
    b = numpy.arange(n) ** 3
    return a + b

def pythonsum(n):
    a = range(n)
    b = range(n)
    c = []

    for i in range(len(a)):
        a[i] = i ** 2
        b[i] = i ** 3
        c.append(a[i] + b[i])

    return c

n = 4000
start = datetime.now()
c = pythonsum(n)
delta = datetime.now() - start
print c[-2:]
print delta.microseconds

start = datetime.now()
c = pythonsum(n)
delta = datetime.now() - start
print c[-2:]
print delta.microseconds