Python 学习入门（38）—— @functools模块
The functools module is for higher-order functions: functions that act on or return other functions. In general, any callable object can be treated as a function for the purposes of this module.
functools 源码路径及内置函数：
利用@functools对函数运行时间，进行计时
代码示例：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# blog.ithomer.net
import time, functools
def timeit(func):
@functools.wraps(func)
def __do__(*args, **kwargs):
start = time.time()
result = func(*args, **kwargs)
print("%s usedtime: %ss" % (func.__name__, time.time() - start))
return result
return __do__
@timeit
def print_str(num):
sum = 0
for i in range(num):
sum += i
print sum
@timeit
def main():
print("print_str(100)")
print_str(100)
print("print_str(10000)")
print_str(10000)
print("print_str(1000000)")
print_str(1000000)
if __name__ == "__main__":
main()运行结果：
print_str(100) 4950 print_str usedtime: 3.60012054443e-05s print_str(10000) 49995000 print_str usedtime: 0.000550985336304s print_str(1000000) 499999500000 print_str usedtime: 0.0614850521088s main usedtime: 0.0623250007629s
说明：运行结果中的红色部分，都是运行计时的结果
示例2：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# blog.ithomer.net
import time, functools
def functools_wrapper(func):
@functools.wraps(func)
def wrapper(*args, **kwargs):
print("call from functools_wrapper...")
start = time.time()
result = func(*args, **kwargs)
print("%s usedtime: %ss" % (func.__name__, time.time() - start))
# return func(*args, **kwargs)
return result
return wrapper
@functools_wrapper
def functools_partial():
print(int('10')) # 10
print(int('10', 2)) # 2
int2 = functools.partial(int, base=2)
print(int2('10')) # 2
print(int2('1010')) # 10
int2 = functools.partial(int, base=8)
print(int2('10')) # 8
print(int2('1010')) # 520
@functools_wrapper
def functools_reduce():
array = [1, 2, 3, 4, 5, 6]
result = reduce((lambda x,y:x*y), array)
print("result = %d" % result) # 720
result = functools.reduce((lambda x,y:x*y), array)
print("result = %d" % result) # 720
def main():
functools_partial()
functools_reduce()
if __name__ == "__main__":
main()运行结果：
call from functools_wrapper... 10 2 2 10 8 520 functools_partial usedtime: 2.00271606445e-05s call from functools_wrapper... result = 720 result = 720 functools_reduce usedtime: 1.21593475342e-05s
参考推荐：
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原始发表：2014年03月01日，如有侵权请联系 cloudcommunity@tencent.com 删除
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