def _lower_ucs4(code_point, data, length, idx, mapped):
    """This is a translation of the function that lowers a character."""
    if code_point == 0x3A3:
        mapped[0] = _handle_capital_sigma(data, length, idx)
        return 1
    return _PyUnicode_ToLowerFull(code_point, mapped)
This is a translation of the function that lowers a character.
numba/cpython/unicode.py