old_contents: # |~~\'    |~~
  # |__/||~~\|--|/~\\  /
  # |   ||__/|__|   |\/
  #      |
  
  import os
  import sys
  
  # Inject vendored directory into system path.
  v_path = os.path.sep.join([os.path.dirname(os.path.realpath(__file__)), 'vendor'])
  sys.path.append(v_path)
  
  
  from .cli import cli
  
  if __name__ == '__main__':
      cli()
  
new_contents: # |~~\'    |~~
  # |__/||~~\|--|/~\\  /
  # |   ||__/|__|   |\/
  #      |
  
  import os
  import sys
  
  # Inject vendored directory into system path.
  v_path = os.path.sep.join([os.path.dirname(os.path.realpath(__file__)), 'vendor'])
  sys.path.insert(1, v_path)
  
  
  from .cli import cli
  
  if __name__ == '__main__':
      cli()
  
subject: use sys.path.insert(1, v_path) instead of sys.path.append(v_path)