docs: def numerify(self, text='###'):
          """
          Replaces all placeholders in given text with randomized values,
          replacing: all hash sign ('#') occurrences with a random digit
          (from 0 to 9); all percentage sign ('%') occurrences with a
          random non-zero digit (from 1 to 9); all exclamation mark ('!')
          occurrences with a random digit (from 0 to 9) or an empty string;
          and all at symbol ('@') occurrences with a random non-zero digit
          (from 1 to 9) or an empty string.
  
          :param text: string to be parsed
          :returns: string with all numerical placeholders filled in
          """
          text = _re_hash.sub(
              lambda x: str(self.random_digit()),
              text)
          text = _re_perc.sub(
              lambda x: str(self.random_digit_not_null()),
              text)
          text = _re_excl.sub(
              lambda x: str(self.random_digit_or_empty()),
              text)
          text = _re_at.sub(
              lambda x: str(self.random_digit_not_null_or_empty()),
              text)
          return text