# 5.11 Simulating Stacks with Lists¶

- Python does not have a built-in stack type.
- Can think of a stack as a constrained list.
- Push using list method `append`.
- Pop using list method `pop` with no arguments to get items in last-in, first-out (LIFO) order.

In [1]:

    stack = []

In [2]:

    stack.append('red')

In [3]:

    stack

Out[3]:

    ['red']

In [4]:

    stack.append('green')

In [5]:

    stack

Out[5]:

    ['red', 'green']

In [6]:

    stack.pop()

Out[6]:

    'green'

In [7]:

    stack

Out[7]:

    ['red']

In [8]:

    stack.pop()

Out[8]:

    'red'

In [9]:

    stack

Out[9]:

    []

In [10]:

    stack.pop()

    ------------------------------------------------------------------------
    IndexError                             Traceback (most recent call last)
    <ipython-input-10-415460d3b717> in <module>
    ----> 1 stack.pop()

    IndexError: pop from empty list

- Also can use a list to simulate a queue.
- Items are retrieved from queues in first-in, first-out (FIFO) order.

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