The current file name is: multiprocessing.py

   #!/usr/bin/env python3
    import os 
    from multiprocessing import Process
    
    def child_proc(name):
        print('child process', name, '[',os.getpid(),']','start running...')
    if __name__ == '__main__':
        print('parent process', os.getpid())
        for i in range(5):
            create_childpid = Process(target=child_proc,args=(str(i),))
            print('process will start...')
            create_childpid.start()
        create_childpid.join()
        print('process end')

Function:

sice@T:~/lxz$ vim multiprocessing.py
sice@T:~/lxz$ chmod +x multiprocessing.py 
sice@T:~/lxz$ ./multiprocessing.py 

Report errors:

Traceback (most recent call last):
  File "./multiprocessing.py", line 3, in <module>
    from multiprocessing import Process
  File "/home/sice/lxz/multiprocessing.py", line 3, in <module>
    from multiprocessing import Process
ImportError: cannot import name 'Process'

The reason for the error is that the file name is the same as the module name

The current file name is: multiprocessing.py
 Module name: from multiprocessing import process

The solution is as follows:
Step 1. (as long as the file name is different from the module name), change the file name to: aaa.py
Under Linux system

sice@T:~/lxz$ mv multiprocessing.py aaa.py      # Rename to aaa.py

Rename in Windows

Step 2. Delete the multiprocessing.pyc file and the pycache folder. All of them have been modified here

 #!/usr/bin/env python3
    import os 
    from multiprocessing import Process
    
    def child_proc(name):
        print('child process', name, '[',os.getpid(),']','start running...')
    if __name__ == '__main__':
        print('parent process', os.getpid())
        for i in range(5):
            create_childpid = Process(target=child_proc,args=(str(i),))
            print('process will start...')
            create_childpid.start()
        create_childpid.join()
        print('process end')

Run over aaa.py That's all right.