Stack on python

def convert_collection_to_stack(_collection):
    return Stack(*_collection.values()) if isinstance(_collection, dict) else Stack(*_collection)


class Stack:
    def __init__(self, *args):
        self._collection = list(args) if len(args) else []

    def push(self, item):
        self._collection.append(item)

    def pop(self):
        return self._collection.pop() if len(self._collection) else None

    def get_stack_as_list(self):
        return self._collection