internals.py 文件源码

def validate_configuration_setting(specification, name, value):
        if not isinstance(value, specification.type):
            if isinstance(specification.type, type):
                type_names = specification.type.__name__
            else:
                type_names = ', '.join(imap(lambda t: t.__name__, specification.type))
            raise ValueError('Expected {} value, not {}={}'.format(type_names, name, repr(value)))
        if specification.constraint and not specification.constraint(value):
            raise ValueError('Illegal value: {}={}'.format(name, repr(value)))
        return value