Multi-process and join usage

# # **************************** 
# # Create a multi-process mode 
# Import OS 
# Import from multiprocessing process 
# 
# Task DEF (): 
# Print ( 'the this Sub process IS') 
# Print (process ID f'sub os.getpid {()} ') 
# Print (f'my ID os.getpid {()} {os.getppid IS PPID ()} ') 
# 
# 
# Print (os.getpid (), __ name__) 
# 
# IF the __name__ ==' __ main__ ': 
# # Note open Code __main__ process must be placed below 
## instances of a process object, let him start a process 
# = the p-process (target = Task) 
# p.start () 
# Print ( 'the this iS parent process') 
# Print ( Process IS f'parent: os.getpid {()} ') 
# Print (' over ') 
# 
# """
# 4280 __main__
# this is parent process
# parent process is:4280
# over
# 5576 __mp_main__
# this is sub process
# sub process id 5576
# my id 5576 ppid is 4280
# """
# # ************************************************
# from multiprocessing import Process
# import os
#
# class Downloarder(Process):
#     # def __init__(self,url,size,name):
#     #     super().__init()
#     #     self.url = url
#     #     self.size = size
#     #     self.name = name
#
#
#     def run(self):
#         print(os.getpid())
#         pass
#
#
# if __name__ == '__main__':
#     m = Downloarder()
#     m.start()
#     m.run()
#     print('parent over',os.getpid())
#
# """
# 1648
# parent over 1648
# 5684
#
# """
# ************************************************
# from multiprocessing import Process
# import os,time
#
# a = 257
#
# def task():
#     global a
#     print("2",a,id(a))
#     a = 200
#
# if __name__ == '__main__':
#     p = Process(target=task)
#
#     p.start()
#
#     time.sleep(5)
#     print(a)
#
# """
# 2 257 2903098186800
# 257
# """
# ************************************************
# from multiprocessing import Process
# import os,time
#
# a = 257
#
# def task():
#     while True:
#         print("子")
#
# if __name__ == '__main__':
#
#
#     p = Process(target=task)
#     p.start()
#     while True:
#         print('主')
#
#         time.sleep(4)
#         print(a)
#
# """
# 主
# 子
# 子
# 子
# 子
# 子
# ......(子)
#
# """
**************************** # 
# 5. join function 

# Import from multiprocessing Process 
# Import OS, Time 
# 
# Task DEF (): 
# for I in Range (100): 
# Print ( 'sub RUN') 
# 
# IF the __name__ == '__main__': 
# P process = (target = Task) 
# p.start () to send commands to the operating system # 
# p.join () # get the main process is finished and then wait for the child to continue 
# 
# Print ( 'over') 
# 
# 
# "" " 
# there p.join () 
# child run 
# ... (97) detected ... 
# run sub- 
unit # run 
# over 
# 
# 
# no p.join () 
# over 
# child run 
# run sub- 
unit # run 
# ....... (97) 
#
# "" " 
# **************************** *** 
# Import from multiprocessing Process 
# Import OS, Time 
# 
# DEF Task1 (Time): 
# for I in Range (1000): 
# Print (F '{name} RUN') 
# 
# DEF Task2 (Time): 
# I in Range for (1000): 
# Print (F '{name} RUN') 
# 
# IF the __name__ == '__main__': 
# Process P1 = (target = Task1, args = ( "P1",)) 
# P1. Start () 
# P2 = process (target = task2, args = ( "P2",)) 
# p2.start () 
# 
# p2.join () # wait for the child to get the main process is finished and then execute 
# p1.join ( ) 
# 
# 
# # to achieve the effect p1, p2 two programs are executed concurrently, and over must be printed only after completion of all program execution
Print # ( 'over') 
# 
# 
# **************************************** ******** 

# using the Join 
# Import OS, Time 
# Import from multiprocessing Process 
# 
# DEF Task (name): 
# for I in Range (. 4): 
# Print (F '{name} RUN') 
# 
# IF the __name__ == '__main__': parameters # args is a sub-process transfer must be ancestral 
# 
# 
# PS = [] 
# for I in Range (. 4): 
# P = process (target = Task, args = (I,)) 
# p.start () 
# ps.append (P) 
# 
# # join one by one the following 
# for I in PS: 
# i.join () 
# 
# Print ( 'over') 
# 
# 
# "" "
# 0 run
# 0 RUN 
# 0 RUN 
# 0 RUN 
#. 1 RUN 
#. 1 RUN 
#. 1 RUN 
#. 1 RUN 
# 2 RUN 
# 2 RUN 
# 2 RUN 
# 2 RUN 
#. 3 RUN 
#. 3 RUN 
#. 3 RUN 
#. 3 RUN 
# over 
# "" " 

# **************************** 
Process multiprocessing Import from 
Import OS, Time 

DEF Task (): 
    the while True: 
        Print ( 'sub RUN', os.getpid ()) 
        # os.getpid () itself ID os.getppid () of the parent class ID 


IF = the __name__ = '__main__': 
    the p-process = (target = Task, args = "old driver process") 
    p.start () 
    p.join () 
    Print (p.name) 

    # # daemon p.daemon
    P.join # () 
    # Print (p.exitcode) # get the process exit code --- use: for example, set 0: correct 1: Account errors, 2: wrong password, 3, wrong address. . . 
    # Print (p.is_alive ()) # view the process is alive 
    # print ( 'zi', p.pid ) # get the process ID 
    # p.terminate () # to terminate the process and start different is not terminated immediately, because operating system there are a lot of things to do 

IF __name__ == '__main__': 
    "" " 
    1. create a server socket object, bind IP, port, start listening for the main process 
    
    2. connect the main loop process 
    
    3. communication child process to the cycle a client will open a sub-process 
    . "" "