问题描述
如果我有一个字典 dict 并且我想检查 dict['key'] 我可以在 try 中这样做块(bleh!)或使用 get() 方法,将 False 作为默认值.
If I had a dictionary dict and I wanted to check for dict['key'] I could either do so in a try block (bleh!) or use the get() method, with False as a default value.
我想对 object.attribute 做同样的事情.也就是说,如果尚未设置,我已经有返回 False 的对象,但这会给我类似
I'd like to do the same thing for object.attribute. That is, I already have object to return False if it hasn't been set, but then that gives me errors like
AttributeError: 'bool' 对象没有属性 'attribute'
AttributeError: 'bool' object has no attribute 'attribute'
推荐答案
与 hasattr 相比,dict.get(key, default) 更直接的类比是 getattr.
A more direct analogue to dict.get(key, default) than hasattr is getattr.
val = getattr(obj, 'attr_to_check', default_value)
(其中 default_value 是可选的,如果未找到则在没有属性时引发异常.)
(Where default_value is optional, raising an exception on no attribute if not found.)
对于您的示例,您将传递 False.
For your example, you would pass False.