python 定時執行指定的函數

# time a function using time.time() and the a @ function decorator

tested with Python24    vegaseat    21aug2005
import time
def print_timing(func):
    def wrapper(arg):
        t1 = time.time()
        res = func(arg)
        t2 = time.time()
        print '%s took %0.3f ms' % (func.func_name, (t2-t1)*1000.0)
        return res
    return wrapper
declare the @ decorator just before the function, invokes print_timing()
@print_timing
def getPrimeList(n):
    """ returns a list of prime numbers from 2 to < n using a sieve algorithm"""
    if n < 2:  return []
    if n == 2: return [2]

# do only odd numbers starting at 3
s = range(3, n+1, 2)
# n**0.5 may be slightly faster than math.sqrt(n)
mroot = n ** 0.5
half = len(s)
i = 0
m = 3
while m <= mroot:
    if s[i]:
        j = (m*m-3)//2
        s[j] = 0
        while j < half:
            s[j] = 0
            j += m
    i = i+1
    m = 2*i+3
return [2]+[x for x in s if x]


if name == "main":
    print "prime numbers from 2 to <10,000,000 using a sieve algorithm"
    primeList = getPrimeList(10000000)
    time.sleep(2.5)
"""
my output -->
prime numbers from 2 to <10,000,000 using a sieve algorithm
getPrimeList took 4750.000 ms
"""</pre>