python - How to access attribute of superclass instance from child class method -

i have following class structure in code:
superclass, a, list of objects subclass, b. class has method, meth, creates variable, var, (by reading file). variable, var, needs accessible method of subclass b. problem after initialising = a(), var attribute of instance a, can't accessed subclass methods using super(). var large array of floats (around 1e5 elements), i'm trying minimise memory usage not making attribute of instance of b (n times!) or passing explicitly methb.

class a(object):   def __init__(self,n):     self.data = [b() _ in xrange(n)]    def __getitem__(self,n):     return self.data[n]    def metha(self):     open('file.txt','r') fp:       self.var = fp.readlines()  class b(a):   def __init__(self):     self.derived_var = []    def methb():     '''this method needs use var defined in meth of above.'''  = a(5) a.metha() b in a:   b.methb() 

is possible in python or bad coding??

first of don't see point of defining b subclass of a. don't seem share functionalites , create circular reference between b , a (in constructor of a) might lead problems.

now question. problem pass a.var methb? this:

class b(a):   def __init__(self):     self.derived_var = []    def methb(self, var):     # code  = a(5) a.meth() b in a:   b.methb(a.var)