Troubles implementing a video game using Python turtle graphics

Question

Basically what I'm trying to do is create a two player game using Python's turtle module. There are two turtles at the bottom which are the players and two circles at the top which act as checkpoints. One turtle is supposed to go back and forth between the two checkpoints—this turtle is the target. The bottom turtles shoot circles at the target.

My issues:

• The target turtle moves way too rapidly.
• The bullets for the turtles at the bottom spawn from the middle of the screen.

Note: There may be some parts of the code which are confusing and/or not needed.

Here's the code:

from turtle import*
import math

def k1():#Enemy Key Commands
    enemy.left(90)
    enemy.forward(10)
    enemy.right(90)

def k2():
    enemy.left(90)
    enemy.backward(10)
    enemy.right(90)

def k3():#Yertle Key Commands
    yertle.left(90)
    yertle.forward(10)
    yertle.right(90)

def k4():
    yertle.left(90)
    yertle.backward(10)
    yertle.right(90)

def k5():
    a=bullet_red()
    a.speed(10)
    a.forward(400)
    collision= math.sqrt(math.pow(a.xcor()-yertle.xcor(),2)+math.pow(a.ycor()-yertle.ycor(),2))
    if(collision<10):
        text=enemy.write("Game Over", align="center" , font=("Arial", 16, "normal"))
    a.hideturtle()

def k6():
    a=bullet_blue()
    a.speed(10)
    a.forward(400)
    collision= math.sqrt(math.pow(a.xcor()-yertle.xcor(),2)+math.pow(a.ycor()-yertle.ycor(),2))
    if(collision<10):
        text=enemy.write("Game Over", align="center" , font=("Arial", 16, "normal"))
    a.hideturtle()

def collision(a, b):
    collision= math.sqrt(math.pow(a.xcor()-b.xcor(),2)+math.pow(a.ycor()-b.ycor(),2))
    if(collision<5):
        print("Bottom Player Wins")
        print("Game Over")


def bullet_red():
    bullet=Turtle("circle")#Description For Bullet
    bullet.color("red")
    bullet.penup()
    bullet.goto(enemy.pos())
    bullet.setheading(180)
    bullet.right(90)
    return bullet

def bullet_blue():
    bullet=Turtle("circle")#Description For Bullet
    bullet.color("blue")
    bullet.penup()
    bullet.goto(yertle.pos())
    bullet.setheading(180)
    bullet.right(90)
    return bullet

ops = Screen()
ops.setup(500, 500)
ops.onkey(k1, "a")#Enemy
ops.onkey(k2, "d")#Enemy
ops.onkey(k3, "Left")#Yertle
ops.onkey(k4, "Right")#Yertle
ops.onkey(k5, "w")#Shoot(Enemy)
ops.onkey(k6, "Up")#Shoot(Enemy)
ops.listen()



checkpoint_1=Turtle(shape="circle")#Turtle Description for Checkpoint 1
checkpoint_1.color("red")
checkpoint_1.setheading(180)
checkpoint_1.right(90)
checkpoint_1.penup()
checkpoint_1.setx(-220)
checkpoint_1.sety(230)
checkpoint_1.speed(0)
#_____________________________

checkpoint_2=Turtle(shape="circle")#Turtle Description for Checkpoint 2
checkpoint_2.color("red")
checkpoint_2.setheading(180)
checkpoint_2.right(90)
checkpoint_2.penup()
checkpoint_2.setx(220)
checkpoint_2.sety(230)
checkpoint_2.speed(0)

#____________________________
runner=Turtle(shape="turtle")#Turtle Description for Checkpoint 2
runner.color("yellow")
while(runner!=collision):
    runner.penup()
    runner.goto(checkpoint_1.pos())
    runner.goto(checkpoint_2.pos())
    runner.speed(0)
    #_____________________________

enemy=Turtle(shape="turtle")#Turtle Description for Player 1
enemy.color("red")
enemy.setheading(180)
enemy.right(90)
enemy.penup()
enemy.setx(-20)
enemy.sety(-200)
enemy.speed(0)

    #_____________________________

yertle = Turtle(shape="turtle")#Turtle Description for Player 2
yertle.color("blue")
yertle.setheading(180)
yertle.right(90)
yertle.penup() 
yertle.setx(20)
yertle.sety(-200)
yertle.speed(0)
    #_____________________________

Answer 1

Below is my rework of your code to get it to just basically play the game -- it still needs work to become a finished program.

from turtle import Turtle, Screen

FONT = ("Arial", 32, "bold")

def k1():  # Enemy Key Commands
    enemy.backward(10)

def k2():
    enemy.forward(10)

def k3():  # Yertle Key Commands
    yertle.backward(10)

def k4():
    yertle.forward(10)

def k5():  # enemy shoot
    bullet.color("red")
    bullet.goto(enemy.position())
    bullet.showturtle()

    bullet.forward(430)

    if bullet.distance(runner) < 10:
        magic_marker.write("Game Over", align="center", font=FONT)

    bullet.hideturtle()

def k6():  # yertle shoot
    bullet.color("blue")
    bullet.goto(yertle.position())
    bullet.showturtle()

    bullet.forward(430)

    if bullet.distance(runner) < 10:
        magic_marker.write("Game Over", align="center", font=FONT)

    bullet.hideturtle()

def move_runner():
    if runner.distance(checkpoint_1) < 5 or runner.distance(checkpoint_2) < 5:
        runner.left(180)
    runner.forward(2)

    screen.ontimer(move_runner, 50)

screen = Screen()
screen.setup(500, 500)

bullet = Turtle("circle", visible=False)  # Description For Bullet
bullet.speed('normal')
bullet.penup()
bullet.setheading(90)

checkpoint_1 = Turtle("circle", visible=False)  # Turtle Description for Checkpoint 1
checkpoint_1.color("red")
checkpoint_1.penup()
checkpoint_1.goto(-220, 230)

checkpoint_2 = checkpoint_1.clone()  # Turtle Description for Checkpoint 2
checkpoint_2.goto(220, 230)

runner = Turtle("turtle", visible=False)
runner.color("orange")
runner.speed('fastest')
runner.penup()
runner.sety(230)

yertle = Turtle(shape="turtle", visible=False)  # Turtle Description for Player 1
yertle.tiltangle(90)  # face one way but move another!
yertle.speed('fastest')
yertle.penup()
yertle.color("blue")
yertle.goto(20, -200)

enemy = yertle.clone()  # Turtle Description for Player 2
enemy.color("red")
enemy.goto(-20, -200)

checkpoint_1.showturtle()
checkpoint_2.showturtle()
runner.showturtle()
yertle.showturtle()
enemy.showturtle()

magic_marker = Turtle(visible=False)  # for writing text

screen.onkey(k1, "a")  # Enemy
screen.onkey(k2, "d")  # Enemy
screen.onkey(k3, "Left")  # Yertle
screen.onkey(k4, "Right")  # Yertle
screen.onkey(k5, "w")  # Shoot(Enemy)
screen.onkey(k6, "Up")  # Shoot(Yertle)
screen.listen()

move_runner()

screen.mainloop()

Your code had errors (as did your comments) but my primary advice is to review the turtle documentation to see all the features available to you -- when writing a game, you need to know what a turtle can do.

I changed the bullets into a single shared bullet -- turtles don't go away when you're finished with them so this seemed better resource-wise. But it's also buggy, however. If you continue with a single bullet model, you'll want to interlock the firing events to prevent overlap. If you instead go with multiple bullets firing at the same, you'll want to add more ontimer events like the runner uses to control their motion.