code: def period_comma():
      
      return RegexBuilder(
          pattern_args=symbols.PERIOD_COMMA,
          pattern_func=lambda x: r"(?<!\.[a-z]){} ".format(x)).regex
docs: Period and comma case.
  
      Match if not preceded by ".<letter>" and only if followed by space.
      Won't cut in the middle/after dotted abbreviations; won't cut numbers.
  
      Note:
          Won't match if a dotted abbreviation ends a sentence.
  
      Note:
          Won't match the end of a sentence if not followed by a space.