Close access to the base class public methods

[RinKaMeAri]

Hi!
Could you imagine any way to block access to the base class public
methods?
Here is an example:
class B:
    def public_method():
        pass

class A(B):
    def public_a_method():
         pass

def a = A()

Is there any way to block the call a.public_method() without any
changes to B class?
Thank you!