from __future__ import print_function

class MyClass:

	num_instances = 0

	def __init__(self, value):
		self.value = value
		MyClass.num_instances += 1

	def __del__(self):
		MyClass.num_instances -= 1

print("There should be no instances yet:", MyClass.num_instances)
inst = MyClass("hello")
print("There should be one instance:", MyClass.num_instances)

def f():
	print("f started with:", MyClass.num_instances)
	f_inst = MyClass("f")
	print("f returning with:", MyClass.num_instances)

f()
# When f returns, the local variable f_inst is deleted so
# there should be exactly as many as we started with
print("There is now:", MyClass.num_instances)