[ Python 常見問題 ] Get all object attributes in Python?

Source From Here 
Question 
Is there a way to get all attributes/methods/fields/etc. of an object in Python? 

vars() is close to what I want, but it doesn't work unless an object has a __dict__, which isn't always true (e.g. it's not true for a list, a dict, etc.). 

How-To 
You can leverage built-in API dir to know all attributes/methods/fields of an object. e.g.: 

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1. >>> class Person:  
2. ...     def __init__(self, name, age):  
3. ...             self.name = name  
4. ...             self.age = age  
5. ...     def a(self):  
6. ...             return self.age  
7. ...     def n(self):  
8. ...             return self.name  
9. ...  
10. >>> john = Person('John', 37)  
11. >>> john.a()  
12. 37  
13. >>> john.n()  
14. 'John'  
15. >>> dir(john)  
16. ['__doc__', '__init__', '__module__', 'a', 'age', 'n', 'name']  

Then you can access the attribute(s) of an object by getattr: 

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1. >>> for attr in john.__dict__.keys():  
2. ...     if attr.startswith('__'):  
3. ...             continue  
4. ...     attr_obj = getattr(john, attr)  
5. ...     if callable(attr_obj):  
6. ...             print('attr \'{}\' is a function or method'.format(attr))  
7. ...     else:  
8. ...             print('attr of {} with value={}'.format(attr, attr_obj))  
9. ...  
10. attr of age with value=37  
11. attr of name with value=John  
12. >>> getattr(john, 'a')  
13. 0x7f0c64438d88>>  

>>> callable(getattr(john, 'a'))  

True  

From above example, you can notice that the __dict__ won't contain method(s)! 

Supplement 
* How to get an attribute from an object in Python