Thread

多线程编程分为两种方式：

1. 实例化Thread

import time
from datetime import datetime
from threading import Thread
def sleep_tast(sleep_time):    
    print(datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
    print(f"sleep {sleep_time} seconds start!")
    time.sleep(sleep_time)
    print(datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
    print(f"sleep {sleep_time} seconds end!")
if __name__ == "__main__":
    start_time = time.time()
    # 当程序启动的时候会默认开启一个主线程    
    # 如何让主线程等到其它线程执行完后才继续执行，  join方法    
    # 主线程给子线程2.5s的时间，如果执行不完也会结束，防止子线程占用资源卡死,setDaemon方法 守护线程    
    t1 = Thread(target = sleep_tast, args = (2,))
    t1.setDaemon(True)
    t1.start()
    t2 = Thread(target = sleep_tast, args = (3,))
    t2.setDaemon(True)
    t2.start()
    # t2.join()    
    time.sleep(2.5)
    end_time = time.time()
    print(f"last_time:{end_time - start_time}")

1. 继承Thrad类

from threading import Thread
import time
from datetime import datetime
class SleepThread(Thread):    
    def __init__(self, sleep_time):        
        self.sleep_time = sleep_time        
        super().__init__()  # 调用父类的init方法
    def run(self):        
        print(datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
        print(f"sleep {self.sleep_time} seconds start!")
        time.sleep(self.sleep_time)
        print(datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
        print(f"sleep {self.sleep_time} seconds end!")
if __name__ == "__main__":    
    start_time = time.time()
    # 当程序启动的时候会默认开启一个主线程    
    # 如何让主线程等到其它线程执行完后才继续执行，  join方法    
    # 主线程给子线程2.5s的时间，如果执行不完也会结束，防止子线程占用资源卡死,setDaemon方法 守护线程     
    t1 = SleepThread(2)
    t1.setDaemon(True)
    t1.start()
    # t1.join()
    t2 = SleepThread(3)
    t2.setDaemon(True)
    t2.start()
    time.sleep(2.5)
    end_time = time.time()
    print(f"last_time:{end_time - start_time}")