How to use one class variable in another class in python

Either

import sys
class A():
    def __init__(self,var1,var2):
        self.var1 = var1
        self.var2 = var2
        pass
class B():
    def __call__(self, a):
        print(a.var1, a.var2)
        #(here I want to use var1 and var2 from class A)

a = A(sys.argv[1],sys.argv[2])
b = B()
b(a)

Or

import sys
class A():
    def __init__(self,var1,var2):
        self.var1 = var1
        self.var2 = var2
        pass
class B():
    def __init__(self, a):
        self.a = a
    def __call__(self):
        print(self.a.var1, self.a.var2)
        #(here I want to use var1 and var2 from class A)

a = A(sys.argv[1],sys.argv[2])
b = B(a)
b()

use One among these two based on use case

First create instance variables for class A by changing its definition as follows

class A():
    def __init__(self,var1,var2):
        self.var1 = var1
        self.var2 = var2

and then pass the instance of class A to __call__ method of class B as follows

class B():
    def __init__(self, class_A_object):
        self.var1 = class_A_object.var1
        self.var2 = class_A_object.var2

Now you can use the var1 and var2 of class B anywhere inside the instance you created.

object_a = A(var1, var2)
object_b = B(object_a)
print object_b.var1, object_b.var2

Since var1 and var2 are instance variables, you could send the instance of class A to class B:

import sys

class A():
    def __init__(self, var1, var2):
        self.var1 = var1
        self.var2 = var2

class B():        
    def __call__(self, A):
        self.var1 = A.var1
        self.var2 = A.var2

obj_one = A(sys.argv[1], sys.argv[2])
obj_two = B()

obj_two(obj_one)

print(obj_two.var1)
print(obj_two.var2)