code: def load_key(filename, delimiter=r'\s+'):
      r
      # Use our universal function to load the key and mode strings
      scale, mode = load_delimited(filename, [str, str], delimiter)
      if len(scale) != 1:
          raise ValueError('Key file should contain only one line.')
      scale, mode = scale[0], mode[0]
      # Join with a space
      key_string = '{} {}'.format(scale, mode)
      # Validate them, but throw a warning in place of an error
      try:
          key.validate_key(key_string)
      except ValueError as error:
          warnings.warn(error.args[0])
  
      return key_string
docs: r"""Load key labels from an annotation file. The file should
      consist of two string columns: One denoting the key scale degree
      (semitone), and the other denoting the mode (major or minor).  The file
      should contain only one row.
  
      Parameters
      ----------
      filename : str
          Path to the annotation file
      delimiter : str
          Separator regular expression.
          By default, lines will be split by any amount of whitespace.
  
      Returns
      -------
      key : str
          Key label, in the form ``'(key) (mode)'``