Preliminaries

• Take a quick moment to introduce yourself to your group-mates for the day
  • Name
  • Class year
  • Major?
• Fun question of the day: if you had been in charge of naming Karel, what name would you have gone with?

Problem 1: Routing

Problem 2: Letter Encoding

• I am going to go around to each group and give them a secret random letter of the alphabet
• You have a 5x5 world, with Karel starting in the bottom left corner, facing East
• Your task: write out a series of commands that would drop beepers into the shape of the given letter
  • You can choose whether you want a capital or lowercase version of your letter!
• Have one member clearly write out your commands on another sheet of paper, as you are going to share these in a moment!

Problem 3: Letter Decoding!

• I am going to collect all your commands, shuffle them up, and then deal them back to groups
• Your new task: figure out what the other group’s secret letter was!
• I’d recommend not trying to track everything in your head! Use some scratch paper!

Problem 4: Pesky Potholes

• Suppose we wanted Karel to fill all the “holes” in the below world with a beeper

• Your task: Write a program to accomplish this which utilizes at least 3-4 functions (counting your main function)
  • Think about how you might decompose this problem!

Something to Smile About

• Suppose my goal is to have Karel draw out a smiley face with beepers
  • What size of world should we go with?
  • Where should we start Karel?
  • What direction should Karel be facing initially?
• Side goal: showcase strong decomposition and function writing

A Solution

import karel

def main():
    """Draws a smiley face!"""
    move_to_leye()
    draw_eye()
    move_to_reye()
    draw_eye()
    move_to_nose()
    draw_nose()
    move_to_mouth()
    draw_mouth()

def move_to_leye():
    """Moves up to place the first eye"""
    move()

def draw_eye():
    """Places a one beeper eyeball"""
    put_beeper()

def move_to_reye():
    """Moves across the top of the world to the right eye location"""
    turn_right()
    move()
    move()
    move()

def move_to_nose():
    """Moves to the right side of the nose"""
    turn_left()
    turn_left()
    move()
    turn_left()
    move()
    turn_right() # reorienting to prep for line of beepers for nose

def draw_nose():
    """Draws a 2 square flat nose starting from the right"""
    put_beeper()
    move()
    put_beeper()

def move_to_mouth():
    """Moves to the left side of the smile"""
    move()
    turn_left()
    move()

def draw_mouth():
    """Draws a smile from the left to the right"""
    put_beeper()
    move()
    turn_left()
    move()
    put_beeper()
    move()
    put_beeper()
    move()
    turn_left()
    move()
    put_beeper()


def turn_right():
    """Turns Karel to the right"""
    turn_left()
    turn_left()
    turn_left()