With statement, auto-delete object

Is it possible to delete an object form inside its class?

class A():
    def __init__(self):
        print("init")
        self.b="c"
    def __enter__(self):
        print("enter")
        return self
    def __exit__(self, type, value, traceback):
        print("exit")      

with A() as a:
    print(a.b)
print(a.b)

returns:

init
enter
c
exit
c

How comes I still have access to the a object after exiting the with ? Is there a way to auto-delete the object in __exit__?

class A():
    def __init__(self):
        print("init")
        self.b="c"
    def __enter__(self):
        print("enter")
        return self
    def __exit__(self, type, value, traceback):
        print("exit") 
        del self.b

with A() as a:
    print(a.b)
print(a.b)

You can't delete instance of class A itself within __exit__. The best you can do is delete the property b.

init
enter
c
exit
Traceback (most recent call last):
  File "main.py", line 14, in <module>
    print(a.b)
AttributeError: A instance has no attribute 'b'