bre.py 文件源码

def letter_case_props(self, case, in_group, negate=False):
        """Insert letter (ASCII or Unicode) case properties."""

        # Use traditional ASCII upper/lower case unless:
        #    1. The strings fed in are not binary
        #    2. And the the unicode flag was used
        if not in_group:
            v = self.posix_props(
                (self._negate if negate else self._empty) +
                (self._ascii_upper if case == _UPPER else self._ascii_lower)
            )
            v[0] = self._ls_bracket + v[0] + self._rs_bracket
        else:
            v = self.posix_props(
                (self._negate if negate else self._empty) +
                (self._ascii_upper if case == _UPPER else self._ascii_lower)
            )
        return v