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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 _matching_string(matched, string):
 """Return the string as byte or unicode depending on the type of matched, assuming string is an ASCII string. """

        if string is None:
            return string
        if IS_PY2:
            # pylint: disable=undefined-variable
            if isinstance(matched, text_type):
                return text_type(string)
        else:
            if isinstance(matched, bytes) and isinstance(string, str):
                return string.encode(locale.getpreferredencoding(False))
        return string