python线程池和进程池的多参数调用

Posted 2021-06-06 WILLPOWER-

from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor
import time
def calctime(x):
    start = time.perf_counter()
    x()
    end = time.perf_counter()
    return("time cost is", end-start)
def fun(x):
    a, b = x
    time.delay(2)
    return('a is ', a, 'b is ', b)
def muti_thread1():
    with ThreadPoolExecutor() as pool:
        data = [(x, x) for x in range(50)]
        results = pool.map(fun, data)
def thread():
    data = [(x, x) for x in range(50)]
    for i in data:
        fun(i)
def muti_process():
    with ProcessPoolExecutor() as pool:
        data = [(x, x) for x in range(50)]
        results = pool.map(fun, data)
if __name__ == '__main__':
    print(calctime(muti_thread1))
    print(calctime(thread))
    print(calctime(muti_process))

注意事项：

1. 要注意在开启线程的程序中，一定要注意变量的使用是否是赋值、浅拷贝、还是深拷贝，则会影响到线程之间的变量共享使用等！
2. 在开启多进程时候，必须要指定主程序__name__ == ‘main’
3. 使用map是顺序输出，要想不顺序输出，可以使用as_completed
   
   图片来源