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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 _set_transmaps(self):
 """Set translation maps for our standard."""

        if self._std == 'ascii':
            self._lower_chars = string.ascii_lowercase
            self._upper_chars = string.ascii_uppercase

        elif self._std == 'rfc1459':
            self._lower_chars = (string.ascii_lowercase +
                                 ''.join(chr(i) for i in range(123, 127)))
            self._upper_chars = (string.ascii_uppercase +
                                 ''.join(chr(i) for i in range(91, 95)))

        elif self._std == 'rfc1459-strict':
            self._lower_chars = (string.ascii_lowercase +
                                 ''.join(chr(i) for i in range(123, 126)))
            self._upper_chars = (string.ascii_uppercase +
                                 ''.join(chr(i) for i in range(91, 94)))