old_contents: repo_name = '{{ cookiecutter.repo_name }}'
  assert_msg = 'Repo name should be valid Python identifier!'
  
  if hasattr(repo_name, 'isidentifier'):
      assert repo_name.isidentifier(), assert_msg
  else:
      import re
      identifier_re = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*$")
      assert bool(identifier_re.match(repo_name)), assert_msg
  
new_contents: import sys
  
  import cookiecutter
  
  
  # Ensure cookiecutter is recent enough
  cookiecutter_min_version = '1.3.0'
  if cookiecutter.__version__ < cookiecutter_min_version:
      print("--------------------------------------------------------------")
      print("!! Your cookiecutter is too old, at least %s is required !!" % cookiecutter_min_version)
      print("--------------------------------------------------------------")
      sys.exit(1)
  
  
  # Ensure the selected repo name is usable
  repo_name = '{{ cookiecutter.repo_name }}'
  assert_msg = 'Repo name should be valid Python identifier!'
  
  if hasattr(repo_name, 'isidentifier'):
      assert repo_name.isidentifier(), assert_msg
  else:
      import re
      identifier_re = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*$")
      assert bool(identifier_re.match(repo_name)), assert_msg
  
subject: Add check for cookiecutter version - at least 1.3.0 is required now