human
Complete the below
def _fixup_cdef_enums(string, reg=re.compile('=\\s*(\\d+)\\s*<<\\s*(\\d+)')):

    ''''Converts some common enum expressions to constants'
    '''

Give me a the Python code you requested?
assistant
#Here is the Python code you requested.
    def repl_shift(match):
        shift_by = int(match.group(2))
        value = int(match.group(1))
        int_value = ctypes.c_int((value << shift_by)).value
        return ('=    %s' % str(int_value))
    return reg.sub(repl_shift, string)