知道名称，获取obj属性的值

Question

I have a number of constants,variable in which i keep names. 我有许多常量，其中的变量都保留名字。

ATTR_ITEM_NAME = 'pro'

I check if the attribute is attached to an objects: 我检查属性是否附加到对象：

 if hasattr(obj1, ATTR_ITEM_NAME):

then if exist I want the attribute value to be passed to an attribute of an object, something like this: 那么如果存在，我希望将属性值传递给对象的属性，如下所示：

obj2.fm = obj1.ATTR_ITEM_NAME

ATTR_ITEM_NAME being a string and not an attribute is an error, I need something that works; ATTR_ITEM_NAME是字符串而不是属性是错误，我需要一些有效的方法；

Answer 1

Python also has getattr which works like hasattr but returns the value: Python也有getattr ，它类似于hasattr但返回值：

obj2.fm = getattr(obj1, ATTR_ITEM_NAME)

If you are not sure the attribute exists you could: 如果不确定该属性是否存在，则可以：

assign a default value (eg None ) 分配一个默认值（例如None ）
```
 DEFAULT = None obj2.fm = getattr(obj1, ATTR_ITEM_NAME, DEFAULT) 
```

or catch the exception using 或使用捕获异常

 try: obj2.fm = getattr(obj1, ATTR_ITEM_NAME) except AttributeError: pass # or do something else...