class B:
	def __init__(self, ainstance):
		self.ainstance = ainstance
		pass

	def bar(self):
		A.foo(self.ainstance, 'Hi')

class A:
	def __init__(self):
		self.b = B(self)
	
	def foo(self, var):
		print var

	def baz(self):
		self.b.bar()

a = A()
a.baz()