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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def period_comma():
 """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. """

    return RegexBuilder(
        pattern_args=symbols.PERIOD_COMMA,
        pattern_func=lambda x: r"(?<!\.[a-z]){} ".format(x)).regex