#!/usr/bin/env python
import os
import argparse

def main():
	parser = argparse.ArgumentParser()
	parser.add_argument('--run', action="store_true")
	parser.add_argument('--deploy', action="store_true")
	args = parser.parse_args()

	if not any(vars(args).values()):
	    parser.print_help()
	elif args.run:
	    os.system("gunicorn server:app --reload --config gunicorn_config.py")
	elif args.deploy:
	    os.system("git push heroku master")

if __name__ == '__main__':
	main()

#!/usr/bin/env python
import os
import argparse

def run():
	os.system("gunicorn server:app --reload --config gunicorn_config.py")

def deploy():
	os.system("git push heroku master")

def main():
	parser = argparse.ArgumentParser()
	parser.add_argument('--deploy', action="store_true", required=False)
	args = parser.parse_args()

	if args.deploy:
	    deploy()
	else:
		run()

if __name__ == '__main__':
	main()

Move run() out of main() and make --run the default.