Python code?
1. class father:
2. def __init__(self, param):
3. self.o1 = param
4.
5. class child(father):
6. def __init__(self, param):
7. self.o2 = param
8.
9. >>>obj = child(22)
10. >>>print "%d %d" % (obj.o1, obj.o2)
Explanation: self.o1 was never created.