https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:methods/e/trace-instance-methods 2025-11-12T19:50:41.218922298Z Trace instance methods Trace instance method calls and interpret method definitions. Kim Merrill exercise https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:class-design/pc/challenge-elevator-dispatch 2026-02-27T08:40:43.877091507Z Challenge: Elevator dispatch Practice writing instance methods to simulate an elevator's movement. challenge https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:methods/pc/challenge-word-guess 2026-02-19T20:50:30.97637568Z Challenge: Word guess Practice using a class definition to build a letter-guessing game. challenge https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:composition/e/compose-objects 2026-03-24T18:10:51.947153347Z Compose objects Trace class definitions that use composition to store other objects. Kim Merrill exercise https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:composition/pc/challenge-library-catalog 2026-03-12T23:30:34.882083961Z Challenge: Library catalog Practice composing multiple objects to implement a library management system for checking out books. challenge https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:programming-robots/a/instructions-paint-battle 2025-11-20T22:30:40.029956095Z Instructions: Paint battle Apply classes to program a robot that competes to paint the most cells in an arena. These instructions accompany the Paint Battle project. article https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:programming-robots/pp/paint-battle 2026-03-12T23:30:34.882083961Z Project: Paint battle #### Paint the most squares See [Instructions: Paint battle](/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:building-software-with-classes/x5279a44ae0ab15d6:programming-robots/a/instructions-paint-battle). 1. Design a movement strategy for the `BlueBot`. 2. Implement your algorithm in the `.pick_move()` method. 3. Test your robot's strategy against the random `RedBot`. 4. Iterate on your algorithm until the `BlueBot` wins consistently! Each turn, a robot can stay on its current cell or move to an adjacent cell — up, down, left, right, or diagonally. When a robot moves, it paints its color on the cell it just left. How can your robot use what it observes in the `Arena` to plan its next move? project