How can I implement a custom stack and queue in Python?

How can I implement a custom stack and queue in Python?

You can create a custom stack using a list and define methods like push, pop, and peek. Would you like a code example?

Yes, please provide a code example for the stack.

Here's a simple implementation:

class Stack:
    def __init__(self):
        self.items = []

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

    def pop(self):
        return self.items.pop() if not self.is_empty() else None

    def peek(self):
        return self.items[-1] if not self.is_empty() else None

    def is_empty(self):
        return len(self.items) == 0

    def size(self):
        return len(self.items)

Great! How would I implement a queue in a similar way?

You can implement a queue using a list as well. Here's a basic example:

class Queue:
    def __init__(self):
        self.items = []

    def enqueue(self, item):
        self.items.insert(0, item)

    def dequeue(self):
        return self.items.pop() if not self.is_empty() else None

    def is_empty(self):
        return len(self.items) == 0

    def size(self):
        return len(self.items)