python inherit instance variable

gistfile1.py

class A(object):
    def __init__(self):
        self.a = 1
        
    def hoge(self):
        if hasattr(self, "a"):
            return self.a
        else:
            return 0

class B(A):
    def __init__(self):
#        self.a = 1
        self.b = 2

if __name__ == '__main__':
    b = B()
    print b.hoge() # print 0. not 1