I want to be able to subclass a class, and define `__init__` but still run the old `__init__` as well.

To illustrate, say I have the following classes:

```
class A(object):
    def __init__(self):
        self.var1 = 1

class B(A):
    def __init__(self)
        self.var2 = 2
        doInitForA()

```

And I want to be able to do this:

```
instB = B()
print (instB.var1) #1
print (instB.var2) #2

```

Edited as Ignacio Vazquez-Abrams suggested. (Is it possible to edit without bumping?)