code: def extract_extension(path):
      
      filename = os.path.basename(path)
      parts = filename.split(".")
      if len(parts) == 1:
          return filename, None
      else:
          return ".".join(parts[:-1]), parts[-1]
docs: Reads a file path and returns the extension or None if the path
      contains no extension.
  
      :Parameters:
          path : str
              A filesystem path