old_contents: project_slug = '{{ cookiecutter.project_slug }}'
  
  if hasattr(project_slug, 'isidentifier'):
      assert project_slug.isidentifier(), 'Project slug should be valid Python identifier!'
  
  elasticbeanstalk = '{{ cookiecutter.use_elasticbeanstalk_experimental }}'.lower()
  heroku = '{{ cookiecutter.use_heroku }}'.lower()
  docker = '{{ cookiecutter.use_docker }}'.lower()
  
  if elasticbeanstalk == 'y' and (heroku == 'y' or docker == 'y'):
      raise Exception("Cookiecutter Django's EXPERIMENTAL Elastic Beanstalk support is incompatible with Heroku and Docker setups.")
  
new_contents: project_slug = '{{ cookiecutter.project_slug }}'
  
  if hasattr(project_slug, 'isidentifier'):
      assert project_slug.isidentifier(), 'Project slug should be valid Python identifier!'
  
  elasticbeanstalk = '{{ cookiecutter.use_elasticbeanstalk_experimental }}'.lower()
  heroku = '{{ cookiecutter.use_heroku }}'.lower()
  docker = '{{ cookiecutter.use_docker }}'.lower()
  
  if elasticbeanstalk == 'y' and (heroku == 'y' or docker == 'y'):
      raise Exception("Cookiecutter Django's EXPERIMENTAL Elastic Beanstalk support is incompatible with Heroku and Docker setups.")
  
  if docker == 'n':
  	import sys
  
  	python_major_version = sys.version_info[0]
  
  	if python_major_version == 2:
  		sys.stdout.write("WARNING: Cookiecutter Django does not support Python 2! Stability is guaranteed with Python 3.4+ only. Are you sure you want to proceed? (y/n)")
  
  		yes_options = set(['y'])
  		no_options = set(['n', ''])
  		choice = raw_input().lower()
  		if choice in no_options:
  			sys.exit(1)
  		elif choice in yes_options:
  			pass
  		else:
  			sys.stdout.write("Please respond with %s or %s" 
  				% (', '.join([o for o in yes_options if not o == ''])
  					, ', '.join([o for o in no_options if not o == ''])))
  
subject: Add a pre-hook that checks the python version (#1142)