Python: Getting python class has no attribute

A does not have an attribute f2, but it does have an attribute f1 that calls a function f2. f2 is not an instance attribute.

In this case c is no longer an instance attribute, or data attribute, it is now just a local variable. This may or may not be what you were going for.

class D:
    def __init__(self):
        self.a = 1

    def f1(self):
        # Instance attribute declared outside of __init__
        self.b = 2

        def f2():
            c = 3
            print(self.a, self.b, c)
        f2()

Depending on your development environment you may or may not get a warning about instance attributes being declare outside of the __init__ function. It isn't necessary that you declare them this way, however, it improves readability.

class B:
    def __init__(self):
        self.a = 1
        self.b = 2
        self.c = 3

    def f1(self):
        def f2():
            print(self.a, self.b, self.c)
        f2()

This next block is slightly more explicit in what it says about the intent of the code.

class A:
    def __init__(self):
        self.a = 1
        self.b = 2
        self.c = 3

    def f1(self):
        def f2():
            return '{} {} {}'.format(self.a, self.b, self.c)
        return f2()

Perhaps you want f2() to be called using method attributes of the self argument in which case:

class A2:
    def __init__(self):
        self.a = 1
        self.b = 2
        self.c = 3

    def f2(self):
        print(self.a, self.b, self.c)

    def f1(self):
        """Do something that requires calling the self.f2()
        print function.
        """
        self.f2()

You do not need self when calling the nested function and nor does it need to be contained in the function signature:

class A:
   def __init__(self):
     self.a=1
   def f1(self):
     self.b=2
     def f2():
        c=3
        print(self.a,self.b, c)
     f2()

model = A()
model.f1()

Output:

1, 2, 3

Its not clear to me that you actually need to define a function within a method just to call it.

So, your code could just as easily be this:

class A:
    def __init__(self):
        self.a = 1

    def f1(self):
        self.b = 2
        self.f2()

    def f2(self):
        self.c = 3
        print(self.a, self.b, self.c)

model = A()
model.f1()

Output:

1 2 3