Make Key Bindings Work For Space Invaders Game

I'm doing a tutorial to make 'Space Invaders' in order to learn Python but I'm encountering an issue in binding my keys. No matter what keys I change the move_left and move_right f

Solution 1:

The problem is with these two lines of code:

wn.onkey(move_left(), "Left")
wn.onkey(move_right(),"Right")

You don't want to call move_left(), you want to pass move_left to be called by the event handler when the key is pressed:

wn.onkey(move_left, 'Left')
wn.onkey(move_right, 'Right')

By including the parentheses, you pass the return value of move_left() which is None, effectively disabling the event instead of enabling it!

Here's a rework of your code with the above fix:

from turtle import Screen, Turtle

screen = Screen()
screen.bgcolor('black')
screen.title("Space invaders")

# Border
border_pen = Turtle()
border_pen.hideturtle()
border_pen.pensize(3)
border_pen.speed('fastest')
border_pen.color('white')

border_pen.penup()
border_pen.setposition(-300, -300)
border_pen.pendown()

for _ inrange(4):
    border_pen.forward(600)
    border_pen.left(90)

# Create the player turtle
player = Turtle()
player.shape('triangle')
player.speed('fastest')
player.color('blue')
player.penup()

player.setposition(0, -250)
player.setheading(90)

playerspeed = 15# Move player left and rightdefmove_left():
    x = player.xcor() - playerspeed
    player.setx(x)

defmove_right():
    x = player.xcor() + playerspeed
    player.setx(x)

# Keyboard bindings
screen.onkey(move_left, 'Left')
screen.onkey(move_right, 'Right')

screen.listen()
screen.mainloop()