using a list as a stack

[buran]

Before "reinventing the wheel", check collections.deque. That's what you want, even if you need to inherit from the built-in class.

Deques are a generalization of stacks and queues (the name is pronounced “deck” and is short for “double-ended queue”). Deques support thread-safe, memory efficient appends and pops from either side of the deque with approximately the same O(1) performance in either direction.