timeit模块

用法记录：

stmt = '''
def repeat( f, a0 ):
    yield a0
    while True:
        a0 = f(a0)
        yield a0

n = 2   #求2的平方根
r = repeat( lambda x : (x+n/x)/2 ,1)
for i in range(4):
    #print( next(r) )
    next(r)
'''
print(  "timeit1 = %f" % timeit.timeit( stmt=stmt )  )

更多参考：https://www.cnblogs.com/Uncle-Guang/p/8796507.html