指定线程数的方式实现python多线程及多线程获取返回值

# coding=utf-8
import threading, time


# 1、自己写代码实现，利用全局变量保存线程执行结果



def get_detail_video(vid):
    print('-->', vid)
    time.sleep(2)

datas = []
ths = []

for i in range(10):
    th = threading.Thread(target=get_detail_video, args=(i, datas,))
    th.start()
    ths.append(th)
    if len(ths) >= 3:
        for t in ths:
            t.join()
        ths.clear()
for t in ths:
    t.join()


# 2、重写模块，直接获取每个线程执行结果

# coding=utf-8
from threading import Thread
import time


class MyThread(Thread):
    def __init__(self, func, args):
        super(MyThread, self).__init__()
        self.func = func
        self.args = args

    def run(self):
        self.result = self.func(*self.args)

    def get_result(self):
        try:
            return self.result
        except Exception:
            return None


def a(x, y):
    time.sleep(2)
    return x+y


def b(x, y):
    time.sleep(2)
    return x+y


at = []
t1 = MyThread(a, args=(1,2,))
at.append(t1)
t2 = MyThread(b, args=(10,20,))
at.append(t2)
print(len(at))

ss_tt = time.time()

for t in range(len(at)):
    aa = at[t]
    aa.start()

for t in at:
    t.join()

r1 = t1.get_result()
print(' MyThread__%s 耗时: %s, result = %s' % (1, time.time() - ss_tt, r1))
r2 = t2.get_result()
print(' MyThread__%s 耗时: %s, result = %s' % (2, time.time() - ss_tt, r2))


ss_tt = time.time()
r1 = a(1,2)
print(' MyThread__%s 耗时: %s, result = %s' % (1, time.time() - ss_tt, r1))

r2 = b(10,20)
print(' MyThread__%s 耗时: %s, result = %s' % (2, time.time() - ss_tt, r2))







# 3、 利用线程池 模块

import threadpool


excel_datas = [1, 2, 3]


def run_xhs(i):
    return i


# 回调函数，接受的参数（请求本身，和请求工作函数执行结果）可以省略  
spider_results = []

def get_result(tt_requests, result):
    global spider_results
    spider_results.append(result)

tt_pool = threadpool.ThreadPool(2)    # 指定线程数为2
tt_requests = threadpool.makeRequests(run_xhs, excel_datas, get_result)  # 函数名， 列表
for tt_req in tt_requests:
    tt_pool.putRequest(tt_req)
tt_pool.wait()

if spider_results:
    print('spider_results = ', len(spider_results))
    write_excel_data(spider_results, excel_name)


# spider_results =  3 [1, 2, 3]