More cabbage, more!

In this section, you are going to develop a way of having multiple space cabbages (food) moving around the screen for your turtle to chomp. You are going to do this using Python Lists and Loops.

Step 1.

First, we create the maximum number of cabbages and an empty list by editing the # Create food section with the following code:

# Create food
maxFoods = 6
foods = []

Step 2.

Next, you create a for loop using maxFoods as the range updating the code:

From this:

food = turtle.Turtle()
food.color("lightgreen")
food.shape("circle")
food.penup()
food.speed(0)
food.setposition(random.randint(-290, 290), random.randint(-290, 290))

To this:

for count in range(maxFoods):
    new_food = turtle.Turtle()
    new_food.color("lightgreen")
    new_food.shape("circle")
    new_food.penup()
    new_food.speed(0)
    new_food.setposition(random.randint(-290, 290), random.randint(-290, 290))
    foods.append(new_food)

We use the append() method to add our maximum number of cabbages to the list. This means foods.[0] is a turtle object, foods.[1] is a turtle object etc. etc.

Step 3.

Now, you need to do the same thing for moving the turtle within the # Move Food around section by changing

this:

# Move food around
    food.forward(3)

to:

# Move food around
    for food in foods:
        food.forward(3)

And then indent the boundary checking code so it sits inside your new #Move Food around loop, changing

this:

    # Boundary Food Checking x coordinate
    if food.xcor() > 290 or food.xcor() <- 290:
        food.right(180)

    # Boundary Food Checking y coordinate
    if food.ycor() > 290 or food.ycor() <- 290:
        food.right(180)

to:

    #Move Food around
    for food in foods:
        food.forward(3)

        #Boundary Food Checking x coordinate
        if food.xcor() > 290 or food.xcor() < -290:
           food.right(180)

        #Boundary Food Checking y coordinate
        if food.ycor() > 290 or food.ycor() < -290:
           food.right(180)

Step 4.

Now let’s move (copy and paste) your food collision checking code inside the food movement loop. Make sure you indent it so that your code looks like:

    #Move food around
    for food in foods:
        food.forward(3)

       #Boundary Food Checking x coordinate
        if food.xcor() > 290 or food.xcor() <-290:
           food.right(180)

        #Boundary Food Checking y coordinate
        if food.ycor() > 290 or food.ycor() <-290:
           food.right(180)

        # Collision checking
        if isCollision(player, food):
            food.setposition(random.randint(-290, 290), random.randint(-290, 290))
            food.right(random.randint(0, 360))

Step 5.

Save the game as kbgame7 and run your module.

You now have multiple cabbages moving around your screen. However, the screen can start to look a bit jumpy. To fix this, we can add the tracer method to the program. This tells the computer not to refresh the screen each time and speeds up the animation.

Step 6.

Add the tracer method by typing the following at the end of the #Set up screen area:

wn.tracer(3)

Step 7.

Save and run your module.

You can play with your code by increasing the maxFood number.

Your code should now look like this:

#Turtle Graphics Game
import turtle
import math
import random

#Set up screen
turtle.setup(650,650)
wn = turtle.Screen()
wn.bgcolor("Navy")
wn.tracer(3)

#Draw border
mypen = turtle.Turtle()
mypen.color("white")
mypen.penup()
mypen.setposition(-300,-300)
mypen.pendown()
mypen.pensize(3)
for side in range(4):
    mypen.forward(600)
    mypen.left(90)
mypen.hideturtle()

#Create player turtle
player = turtle.Turtle()
player.color("darkorange")
player.shape("turtle")
player.penup()
player.speed(0)


#Create food
maxFoods = 6
foods = []

for count in range(maxFoods):
    new_food = turtle.Turtle()
    new_food.color("lightgreen")
    new_food.shape("circle")
    new_food.penup()
    new_food.speed(0)
    new_food.setposition(random.randint(-290, 290), random.randint(-290, 290))
    foods.append(new_food)

#Set speed variable
speed = 1

#Define functions

def turn_left():
    player.left(30)

def turn_right():
    player.right(30)

def increase_speed():
    global speed
    speed += 1

def isCollision(t1, t2):
       d = math.sqrt(math.pow(t1.xcor()-t2.xcor(),2) + math.pow(t1.ycor()-t2.ycor(),2))
       if d < 20:
           return True
       else:
           return False

#Set keyboard bindings
turtle.listen()
turtle.onkey(turn_left, "Left")
turtle.onkey(turn_right, "Right")
turtle.onkey(increase_speed, "Up")


while True:
    player.forward(speed)

    #Boundary Checking x coordinate
    if player.xcor() > 290 or player.xcor() < -290:
        player.right(180)
    #Boundary Checking y coordinate
    if player.ycor() > 290 or player.ycor() < -290:
        player.right(180)

    #Move Food around
    for food in foods:
        food.forward(3)

        #Boundary Food Checking x coordinate
        if food.xcor() > 290 or food.xcor() < -290:
           food.right(180)

        #Boundary Food Checking y coordinate
        if food.ycor() > 290 or food.ycor() < -290:
           food.right(180)

        #Collision checking
        if isCollision(player, food):
           food.setposition(random.randint(-290, 290), random.randint(-290, 290))
           food.right(random.randint(0,360))

Time to celebrate

Congratulations Module 7 Completed