python - 必须使用 x 实例作为第一个参数调用未绑定(bind)方法 f() (改为使用 str 实例)

Question

这是我的类(class):

class GoogleCloudLayer:

    def deleteMachine(self, machineName):
        return machineName + ' is dead. (stubbed)'

它有效:

>>> gc = GoogleCloudLayer()
>>> gc.deleteMachine('test')
test is dead (stubbed)

但我想在测试中使用，并且希望在其上定义 assert_ Called_with 方法:

from mock import MagicMock
#Stubbing with itself just so it will have the `assert_called_with` method defined on it
GoogleCloudLayer.deleteMachine = MagicMock(side_effect = GoogleCloudLayer.deleteMachine)

但后来我明白

>>> gc = GoogleCloudLayer()
>>> gc.deleteMachine('test')
unbound method deleteMachine() must be called with GoogleCloudLayer instance as first argument (got str instance instead)

如果我将生产代码更改为 gc.deleteMachine(gc, 'test') 它就可以工作。 但我们不希望这样，不是吗？

Answer 1

lambda 在这种情况下可能很有用，请尝试:

GoogleCloudLayer.createMachine = MagicMock(side_effect = lambda *args, **kwargs: GoogleCloudLayer.createMachine)