restarting main.py without circular import error

Question

I am trying to restart my main.py after the program has finished running. However, when I go into the last file (unlock.py) then put at the end of the script:

from main import *

main()

I get a circular import error. I am not sure a way to work around this so if anyone knows, your help would be greatly appreciated. If you have any questions, feel free to ask.

why are you importing a module at the end of the script? – sage07 Jun 11 '20 at 03:57 — sage07, Jun 11 '20 at 03:57
@sage07 to restart the program as main.py is the runner – Eden Jun 11 '20 at 03:59 — Eden, Jun 11 '20 at 03:59

Yogesh Aggarwal · Accepted Answer · 2020-06-11T05:07:46.653

1

You can use the execv method of os module:

import os
import sys

os.execv(__file__, sys.argv)

If you're getting any permission errors:

os.execv(sys.executable, 
         [sys.executable, os.path.join(sys.path[0], __file__)] + sys.argv[1:])

To disable warnings:

import warnings
warnings.filterwarnings("ignore")

edited Jun 11 '20 at 05:07

answered Jun 11 '20 at 04:02

Yogesh Aggarwal

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Though you'll need to replace `__file__` with `'main.py'`. – Daniel Walker Jun 11 '20 at 04:04
It will work because the `__file__` contains the name of the file we're running. – Yogesh Aggarwal Jun 11 '20 at 04:05
Right but he'd be calling `os.execv` from unlock.py. – Daniel Walker Jun 11 '20 at 04:07
do I need to import anything for this? – Eden Jun 11 '20 at 04:07
this works but I get this error: PermissionError: [Errno 13] Permission denied – Eden Jun 11 '20 at 04:09
Is main.py executable or are you invoking it with the Python interpreter explicitly? – Daniel Walker Jun 11 '20 at 04:10
I did chmod +x main.py now I get this error: Exec format error @DanielWalker – Eden Jun 11 '20 at 04:22
I get this error: `UserWarning: resource_tracker: There appear to be 1 leaked semaphore objects to clean up at shutdown warnings.warn('resource_tracker: There appear to be %d '` @YogeshDeveloper – Eden Jun 11 '20 at 04:56
It's just a warning of using extra resources. Program ran? – Yogesh Aggarwal Jun 11 '20 at 05:02
Thank you! It is working but is there a way to get that warning to not display? @YogeshDeveloper – Eden Jun 11 '20 at 05:04
I definitely will accept, except the warning is still showing. This is what my code looks like: import time import sys import os import warnings `def redo(): time.sleep(5) os.execv(sys.executable, [sys.executable, os.path.join(sys.path[0], 'main.py')] + sys.argv[1:]) warnings.filterwarnings("ignore")` – Eden Jun 11 '20 at 05:15
You should add the warning filter at the top of your code – Yogesh Aggarwal Jun 11 '20 at 05:16
I added it just below my imports and it is still not working... – Eden Jun 11 '20 at 05:16
You should take a look at this: https://stackoverflow.com/questions/14463277/how-to-disable-python-warnings – Yogesh Aggarwal Jun 11 '20 at 05:21

Daniel Walker · Answer 2 · 2020-06-11T04:14:35.420

Without seeing the structure of your program, the best recommendation I can give is to pass your main function around as an argument. That way, in unlock.py, you don't need to import the main module.

Consider this simple example:

main.py

import unlock

def main(function_to_pass):
    # do stuff
    unlock.some_func(function_to_pass,*rest_of_args)

if __name__ == '__main__':
    main(main)

unlock.py

def some_func(function_to_call,*args):
   # do stuff
   if some_condition:
        function_to_call()

EDIT: I realized that you don't need to pass main into itself. main can simply reference itself. That is,

def main():
    # do stuff
    unlock.some_func(main,*args)

can you expand on this? I am a bit confused – Eden Jun 11 '20 at 04:00 — Eden, Jun 11 '20 at 04:00

restarting main.py without circular import error

2 Answers2