Question

What is the difference between class A and class B?

What’s wrong with self?

Why do I need to declare self line by line?

class A(dict):
  def __init__(self):
    self={1:"you", 2:"and me"}
    print "inside of class A",self
class B(dict):
  def __init__(self):
    self[1]="you"
    self[2]="and me"
    print "inside of class B",self

a=A()
print "outside of class A",a
b=B()
print "outside of class B",b

result:

inside of class A {1: 'you', 2: 'and me'}
outside of class A {}
inside of class B {1: 'you', 2: 'and me'}
outside of class B {1: 'you', 2: 'and me'}

Answer 1

  def __init__(self):
    self={1:"you", 2:"and me"}

This doesn’t modify the object passed as self, but re-binds the local variable self to a new dict.