36

I am trying to access a variable from the base class. Here's the parent class:

class Parent(object):
    def __init__(self, value):
        self.some_var = value

And here's the child class:

class Child(Parent):
    def __init__(self, value):
        super(Child, self).__init__(value)

    def doSomething(self):
        parent_var = super(Child, self).some_var

Now, if I try to run this code:

obj = Child(123)
obj.doSomething()

I get the following exception:

Traceback (most recent call last):
  File "test.py", line 13, in <module>
    obj.doSomething()
  File "test.py", line 10, in doSomething
    parent_var = super(Child, self).some_var
AttributeError: 'super' object has no attribute 'some_var'

What am I doing wrong? What is the recommended way to access variables from the base class in Python?

invarbrass
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3 Answers3

43

After the base class's __init__ ran, the derived object has the attributes set there (e.g. some_var) as it's the very same object as the self in the derived class' __init__. You can and should just use self.some_var everywhere. super is for accessing stuff from base classes, but instance variables are (as the name says) part of an instance, not part of that instance's class.

7

The attribute some_var does not exist in the Parent class.

When you set it during __init__, it was created in the instance of your Child class.

Marek P
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0

I got same error, and it was a silly mistake

class one: def init(self): print("init") def status(self): print("This is from 1")

This was my parent class

class two:
def __init__(self):
    print("init")
def status(self):
    super().status()
    print("This is from 2")

This was the child class

a = one()
a.status()

b = two()
b.status()

I was getting same error

   init
This is from 1
init
Traceback (most recent call last):
  File "<string>", line 20, in <module>
  File "<string>", line 12, in status
AttributeError: 'super' object has no attribute 'status'
>

The problem was, I was not entering argument after declaring class two, "class two:" should be "class two(one)" so the solution was.

class two(one):
def __init__(self):
    print("init")
def status(self):
    super().status()
    print("This is from 2")
Abdullah Ansari
  • 1