Understanding the if __name__ == '__main__' Syntax

Syntax:

def run():
	print("the process is starting")
	
def shut_down():
	print("process is shutting down")
	
def email_admin():
	print("Violation noted. Emailing admin...")

# Starting point of the application
if __name__ == '__main__':
	email_admin() # First task running
	shut_down()   # Second task running

It can also be imported:

from process import *

run()
shut_down()

Understanding the syntax

• the variable has underscores in order to not be easy to overwrite by accident

• When you run the file directly the __name__ variable is assigned the __main__ value

• Basically if it is defined then it runs the instructions

• If the if __name__ == '__main__' is not specified then it will run the file as is

  • For the above case it will run run, shut_down, email_admin