1 __threading.Thread

此方法难以控制同时运行的线程数，如同时只运行4个线

示例1

import time
import random
import logging
import threading
# 显示线程名字： threadName
logging.basicConfig(
    format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)d %(threadName)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
    level=logging.DEBUG)
logger = logging.getLogger(__name__)
logger.info('start')
def func(n):
    sec = random.randint(1, 7)
    logger.info('number {}, sleep {}'.format(n, sec))
    time.sleep(sec)
threads = []
for i in range(5):
    t = threading.Thread(target=func, args=(i, ))
    threads.append(t)
for t in threads:       # 开始，执行全部线程 
    t.start()
for t in threads:       # 阻塞，所有线程都结束后才向后执行
    t.join()
logger.info('done')

运行结果

示例2 - 继承Thread类

import time
import random
import logging
import threading
logging.basicConfig(
    format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)d %(threadName)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
    level=logging.DEBUG)
logger = logging.getLogger(__name__)
logger.info('start')
class MyThread(threading.Thread):
    def __init__(self, n):
        super(MyThread, self).__init__()
        self.n = n
    def run(self):
        logger.info('\033[32mstarting {}\033[0m'.format(self.name))
        sec = random.randint(1,7)
        logger.info('sleep {}, value: {}'.format(sec, self.n))
        time.sleep(sec)
        logger.info('\033[36mexiting {}\033[0m'.format(self.name))
threads = []
for i in range(1, 6):
    t = MyThread(i)
    threads.append(t)
for t in threads:
    t.start()
for t in threads:
    t.join()
logger.info('done')

运行结果

2 __mulitprocessing.dummy.Pool

用法类似于多进程池 multiprocessing.Pool multiprocessing.dummy.Pool可以用于类中 multiprocessing.pool.ThreadPool的target不能是类的方法

import time
import logging
from multiprocessing.dummy import Pool as ThreadPool
# from multiprocessing.pool import ThreadPool
logging.basicConfig(
    format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)d %(threadName)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
    level=logging.DEBUG)
logger = logging.getLogger(__name__)
start_time = time.time()
logger.info('start')
def func(n):
    logger.info('starting {}'.format(n))
    sec = 2
    logger.info('number {}, sleep {}'.format(n, sec))
    time.sleep(sec)
    logger.info('exiting {}'.format(n))
p = ThreadPool(3)
for i in range(1, 6):
    p.apply_async(func, args=(i,))
p.close() # 关闭线程池，不可以再添加子线程
p.join()  # 阻塞，之前需要先close
logger.info('done')
logger.info('time used: {:.2f}s'.format(time.time() - start_time))

运行结果

3 _concurrent.futures.ThreadPoolExecutor_

第三方包 可以指定线程数

示例

import time
import logging
from concurrent.futures import ThreadPoolExecutor
logging.basicConfig(
    format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)d %(threadName)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
    level=logging.DEBUG)
logger = logging.getLogger(__name__)
start_time = time.time()
logger.info('start')
def func(n):
    logger.info('starting {}'.format(n))
    sec = 2
    logger.info('number {}, sleep {}'.format(n, sec))
    time.sleep(sec)
    logger.info('exiting {}'.format(n))
t = ThreadPoolExecutor(2)
for i in range(1, 6):
    t.submit(func, i)
t.shutdown()
logger.info('done')
logger.info('time used: {:.2f}s'.format(time.time() - start_time))

运行结果

4 map, map_async, apply, apply_async

https://www.dazhuanlan.com/2019/12/13/5df300f615954/