medium Data Structures

Stack Data Structure

The Brief

DevTools Inc is building an undo/redo system for their editor. Before hooking it into the UI layer they need a proper Stack implementation, not just "a list with append and pop". Build the class with clean semantics and proper empty-state handling.

Acceptance Criteria

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4 Demonstrate push, peek, pop, is_empty, and a caught IndexError

1 Define a class Stack with methods push, pop, peek, is_empty, and size

3 Do not expose the internal list directly — consumers should only use the public methods

2 Raise IndexError with a clear message when pop or peek is called on an empty stack

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solution.py

Python 3

# DevTools — Stack implementation

class Stack:
    def __init__(self):
        pass  # TODO

    # TODO: push, pop, peek, is_empty, size


# TODO: demonstrate push, peek, pop, is_empty, and caught IndexError

Console