JOIN () Method: Use the Cameraup_Thread.Join () method to ensure that the thread is executed and then execute the next Cameraup_thread thread.

Moreover, the JOIN () method does not only stop the next process, and it will prevent this loop from being performed, and the loop in which the thread is located will not be performed down when the thread is not completed.

import threading
import time

def run():
    time.sleep(2)
    Print ('The name of the current thread is:', threading.current_thread (). Name)
    
    time.sleep(2)


if __name__ == '__main__':

    start_time = time.time()

         Print ('This is the main thread:', threading.current_thread (). Name)
    thread_list = []
    for i in range(5):
        t = threading.Thread(target=run)
        t.start()
        nowtime = time.time()
                 PRINT ('Current Process Start Time, determining whether the Join method blocks the thread to prevent the loop execution', NOWTIME)
        t.join()
                 Print ('Determines if the Join method blocks the loop execution If the last thread is not executed,')
         Print ('main thread ends!', threading.current_thread (). name)
         Print ('a total of:', time.time () - start_time)

The execution result of the above code:

As shown in the figure above, i = 1, execute the first thread T, when the thread T is not executed, the program does not perform the print ('judging whether the Join method prevents the execution of the cycle if the JOIN method is When the last thread is not executed, the cycle has not continued because if the loop continues to execute, then a lot of print should be printed. If the JOIN method is blocked, if the execution of the loop is not performed. At the time '), it means that many threads have been stacked. But not, all the Join () methods block the execution of all code behind the thread, and the code behind () only waiting for the thread to perform the end, it can continue.