[PYTHON] Prevent double launch of django commands

The django command is a command that you run with'python manage.py ~'. By default, many useful commands such as shell are provided. Although not explained in detail here, it is possible to create custom commands. And, the custom command etc. are often run as a batch such as crontab, but for some reason I will try not to double start.

custom_command.py

import sys
import commands
from django.core.management.base import BaseCommand

def is_process_exist(process_name):
    """
Returns True if this process is running
    """
    output = commands.getoutput("ps -ef | grep '%s' | grep -v grep | wc -l" % (process_name))
    is_exist = int(output) >= 2

    return is_exist


class Command(BaseCommand):
    def handle(self, *args, **options):
        #Double startup check
        if is_process_exist(__name__.split('.')[-1]):
            sys.exit('duplication!')

        #The following processing ~