Avoid using __name__ == "main" in Python module

I need to implement multiprocessing within a module that is called by a Flask service. I know that I need to use the protection if __name__ == "main" when doing multiprocessing in Python. But in that case I am not sure where the __name__ == "main" should be placed.

The first piece of my code is the Flask service:

import flask  import requests  import Process    app = flask.Flask(__name__)    print("starting app")    @app.route('/query', method=['POST'])  def query():      pl = requests.get_json()      result = Process.process_query(pl)      return result    if __name__ == "main":      app.run(host='0.0.0.0', port=8888)  

The Process module uses multiprocessing in a recursive way:

import multiprocessing  import multiprocessing.pool  from Node import nodeProcess, aggregate, processPoint    class NoDaemonProcess(multiprocessing.Process):      def _get_daemon(self):          return False      def _set_daemon(self, value):          pass      daemon = property(_get_daemon, _set_daemon)    class MyPool(multiprocessing.pool.Pool):      Process = NoDaemonProcess    def process_query(pl):      if pl['nodes']:          pool = MyPool(multiprocessing.cpu_count())          nodeResults = [pool.apply(sub_process_query, node) for node in pl['nodes']]          pool.close()          res = aggregate(nodeResults)      else:          res = processPoint(pl)      return res    def sub_process_query(pl):      return process_query(pl)  

This code is not running properly, and I can see it running a multitude of child process (printing endlessly "starting app"). I assume the if __name__ == 'main' statement is needed somewhere, or a workaround, but I am not sure exactly how.

https://stackoverflow.com/questions/67293212/avoid-using-name-main-in-python-module April 28, 2021 at 11:08AM