from threading import Thread
class threads_object(Thread): def run(self): function_to_run()
class nothreads_object(object): def run(self): function_to_run()
def non_threaded(num_iter): funcs = [] for i in range(int(num_iter)): funcs.append(nothreads_object()) for i in funcs: i.run()
def threaded(num_threads): funcs = [] for i in range(int(num_threads)): funcs.append(threads_object()) for i in funcs: i.start() for i in funcs: i.join()
def function_to_run(): pass
def show_results(func_name, results): print("%-23s %4.6f seconds" % (func_name, results))
if name == "main": import sys from timeit import Timer repeat = 100 number = 1 num_threads = [1, 2, 4, 8] print('Starting tests') for i in num_threads: t = Timer("non_threaded(%s)" % i, "from main import non_threaded") best_result = min(t.repeat(repeat=repeat, number=number)) show_results("non_threaded (%s iters)" % i, best_result) t = Timer("threaded(%s)" % i, "from main import threaded") best_result = min(t.repeat(repeat=repeat, number=number)) show_results("threaded (%s threads)" % i, best_result) print('Iterations complete')
---------------timeit timeit 模块中的三个函数 timeit.timeit(stmt='pass', setup='pass', timer=<default timer>, number=1000000):创建一个Timer实例,参数分别是stmt(需要测量的语句或函数),setup(初始化代码或构建环境的导入语句),timer(计时函数),number(每一次测量中语句被执行的次数) timeit.repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000):创建一个Timer实例,指定整个试验的重复次数,返回一个包含了每次试验的执行时间的列表,利用这一函数可以很方便得实现多次试验取平均的方法。 timeit.default_timer():默认的计时器,一般是time.perf_counter(),time.perf_counter()方法能够在任一平台提供最高精度的计时器(它也只是记录了自然时间,记录自然时间会被很多其他因素影响,例如计算机的负载)
import timeit
def test(): L = [] for i in range(100): L.append(i) if name == 'main': print timeit.timeit("test()", setup="from main import test")
x = list(range(2000000))
t0 = timeit.timeit("x.pop(0)", "from __main__ import x", number=1000)
print("cost {} seconds ".format(t0))