How to iterate on self attributes inside a class in Python3?

Question

I want to iterate on self attributes from self function in Python3, but I have not found any similar. I found how to do it outside the class here.

My question is, is it possible?

class Foo:

    def __init__(self, attr1, attr2):
        self.attr1 = attr1
        self.attr2 = attr2

    def method1(self):
        #Return sum of the values of the self attributes
        pass

you want to iterate through `attr1`, `attr2`? – Azat Ibrakov May 30 '17 at 06:13 — Azat Ibrakov, May 30 '17 at 06:13
Yep, themiurge and Gustavo comment correct answer below. – Sergio Rodríguez Calvo May 30 '17 at 06:18 — Sergio Rodríguez Calvo, May 30 '17 at 06:18

themiurge · Answer 1 · 2017-05-30T06:32:37.747

4

You can access all attributes via the __dict__ member:

class Foo:

    def __init__(self, attr1, attr2):
        self.attr1 = attr1
        self.attr2 = attr2

    def method1(self):
        return sum(self.__dict__.values())

You can also use vars (thanks to Azat Ibrakov and S.M.Styvane for pointing this out):

    def method1(self):
        return sum(vars(self).values())

Here is a nice discussion on __dict__ vs. vars().

edited May 30 '17 at 06:32

answered May 30 '17 at 06:14

themiurge

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2

You can make it simply `sum(self.__dict__.values())` – Gustavo Bezerra May 30 '17 at 06:15
2

or use [`vars`](https://docs.python.org/2/library/functions.html#vars): `sum(vars(self).values())` – Azat Ibrakov May 30 '17 at 06:20

score 3 · Accepted Answer · answered May 30 '17 at 06:23

3

I am not a big fan of using __dict__ for simple things. You should use vars to return a dict of your instance attributes

>>> class Foo(object):
...     def __init__(self, attr1, attr2):
...         self.attr1 = attr1
...         self.attr2 = attr2
...     def method1(self):
...         return sum(vars(self).values())
... 
>>> Foo(2, 4).method1()
6

answered May 30 '17 at 06:23

styvane

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It is correct, that works fine. But, What is the differences? Performance, maybe? – Sergio Rodríguez Calvo May 30 '17 at 06:52
In other response themiurge links this [discussion](https://stackoverflow.com/questions/21297203/use-dict-or-vars). – Sergio Rodríguez Calvo May 30 '17 at 07:27

How to iterate on self attributes inside a class in Python3?

2 Answers2