How to initialize a Python multiprocessing Process whose target takes no args?

Question

rough code:

from multiprocessing import Process

def getPAprofilesPages():
    #do stuff here

def getPBprofilesPages():       
    #do stuff here

P1 = Process(target = getPAprofilesPages, args = [] )
P2 = Process(target = getPBprofilesPages, args = [] )

Notice that the functions take no arguments. I've tried to set args equal to None, (), (,) and [] as seen above, as well as completely omit it from the initialization. In any event, I get the same error when trying to run P1.start() or P2.start() in the interpreter:

>>> Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\******\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 105, in spawn_main
    exitcode = _main(fd)
  File "C:\Users\******\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 115, in _main
    self = reduction.pickle.load(from_parent)
AttributeError: Can't get attribute 'getPAprofilesPages' on <module '__main__' (built-in)>

Answer 1

The following code works fine in a script

def main():
    ...
    all your other code goes here
    ... 
    from multiprocessing import Process
    P1 = Process(target = getPAprofilesPages )
    P2 = Process(target = getPBprofilesPages )
    P1.start()
    P2.start()

def getPAprofilesPages():
    #do stuff here
    pass

def getPBprofilesPages():
    #do stuff here
    pass

if __name__ == '__main__':
    main()

However, you say you are running it in the interpreter, and that is where your problem lies with the fact that you can't use multiprocessing package in interactive Python.

I know this wasn't the answer you were looking for, but it explains your error. You can read more in that link about a workaround.