Get a XML response and tries to convert it to Python base object

def auto_type(s):
    """ Get a XML response and tries to convert it to Python base object
    """
    if isinstance(s, bool):
        return s
    elif s is None:
        return ''
    elif s == 'TRUE':
        return True
    elif s == 'FALSE':
        return False
    else:
        try:
            try:
                # telephone numbers may be wrongly interpretted as ints
                if s.startswith('+'):
                    return s
                else:
                    return int(s)
            except ValueError:
                return float(s)

        except ValueError:
            return s