Python Turtle Graphics window crashes

Question

def whatever()

def whatever2()

While trying to create battleships in python turtle i ran into an issue. I'm using def functions. But everytime the first def function finishes, the turtle graphics window crashes. I tried using turtle.done() after the first def function which prevents it from crashing. However by doing this it won't execute the second def function.

Whole code on request:

    import turtle
i=0
def speelveld():
    turtle.ht()
    x=200
    y=200
    turtle.tracer(10, 0)
    for i in range(10):
        y-=40
        turtle.penup()
        turtle.goto(0,y)
        turtle.pendown()
        x=200
        for i in range(10):
            x-=40
            turtle.goto(x,y)
            for i in range(4):
                turtle.forward(40)
                turtle.left(90)
    y=170
    for i in range(10):
        coordsN = ['1','2','3','4','5','6','7','8','9','10']
        turtle.penup()
        turtle.goto(-220,y)
        turtle.pendown()
        turtle.write(coordsN[i],font=("Calibri", 14, "normal"))
        y-=40
        i=+1
    i=0
    x=-180
    for i in range(10):
        coordsL = ['A','B','C','D','E','F','G','H','I','J']
        turtle.penup()
        turtle.goto(x,205)
        turtle.pendown()
        turtle.write(coordsL[i],font=("Calibri", 14, "normal"))
        x+=40
        i=+1   

speelveld()
x=y=0
def veldkleuren():
    gok = input('Typ een coördinaat in: ')
    if '1' in gok:
        y=150
    elif '2' in gok:
        y=110
    elif '3' in gok:
        y=70
    elif '4' in gok:
        y=30
    elif '5' in gok:
        y=-10
    elif '6' in gok:
        y=-50
    elif '7' in gok:
        y=-90
    elif '8' in gok:
        y=-130
    elif '9' in gok:
        y=-170
    elif '10' in gok:
        y=-210
    else:
        print('Ongeldige invoer')
    if 'A' in gok:
        x=-190
    elif 'B' in gok:
        x=-150
    elif 'C' in gok:
        x=-110
    elif 'D' in gok:
        x=-70
    elif 'E' in gok:
        x=-30
    elif 'F' in gok:
        x=10
    elif 'G' in gok:
        x=50
    elif 'H' in gok:
        x=90
    elif 'I' in gok:
        x=130
    elif 'J' in gok:
        x=170
    else:
        print('Ongeldige invoer')

    turtle.penup()
    turtle.goto(x,y)
    turtle.pendown()
    turtle.write('X',font=("Calibri", 39, "normal"))

veldkleuren()
exit = input('press enter to exit')

The first def is for drawing the battleships playingfield.

Second def is take an input and mark an 'X'on the spot of the input.

Answer 1

I am getting errors of

UnboundLocalError: local variable 'x' referenced before assignment UnboundLocalError: local variable 'y' referenced before assignment

Moving the initialization of x and y inside the second function fixes it.

Answer 2

Below is a rework of your code that attempts to remove the repetitive code (always a source of trouble) and fix some bugs.

One bug is that you have '1' and '10' as input possibilities -- as written, the '1' in '10' will trigger first so '10' will never trigger. I've fixed it in my rework simply by using '0' - '9', ie all unique characters, but there are other ways to solve this problem.

Also note that in code like this:

for i in range(10):
        # ...
        i=+1

The last line setting i makes no difference and can be removed. Even if you did i += 1 , it still wouldn't matter. The loop resets i .

Finally, the turtle pen does not have to be down to call .write() .

import turtle

SMALL_FONT = ("Calibri", 14, "normal")
LARGE_FONT_SIZE = 39
LARGE_FONT = ("Calibri", LARGE_FONT_SIZE, "normal")

coordsN = {'0': 180, '1': 140, '2': 100, '3': 60, '4': 20, '5': -20, '6': -60, '7': -100, '8': -140, '9': -180}

coordsL = {'A': -180, 'B': -140, 'C': -100, 'D': -60, 'E': -20, 'F': 20, 'G': 60, 'H': 100, 'I': 140, 'J': 180}

def speelveld():
    turtle.hideturtle()
    turtle.tracer(0)

    y = 200

    for _ in range(10):
        y -= 40
        turtle.penup()
        turtle.goto(0, y)
        turtle.pendown()
        x = 200

        for _ in range(10):
            x -= 40
            turtle.goto(x, y)

            for _ in range(4):
                turtle.forward(40)
                turtle.left(90)
    turtle.penup()
    turtle.setx(-220)
    y = 170

    for i in range(10):
        turtle.sety(y)
        turtle.write(i, align='right', font=SMALL_FONT)
        y -= 40

    turtle.sety(205)
    x = -180

    for i in range(10):
        turtle.setx(x)
        turtle.write(chr(ord('A') + i), align='center', font=SMALL_FONT)
        x += 40

    turtle.tracer(1)

def veldkleuren():
    x = y = 0

    gok = input('Typ een coördinaat in: ')

    for column in coordsL:
        if column in gok:
            x = coordsL[column]
            break
    else:  # no break
        exit('Ongeldige invoer')

    for row in coordsN:
        if row in gok:
            y = coordsN[row]
            break
    else:  # no break
        exit('Ongeldige invoer')

    turtle.penup()
    turtle.goto(x, y - LARGE_FONT_SIZE/2)

    turtle.write('X', align='center', font=LARGE_FONT)

speelveld()

veldkleuren()

input('press enter to exit')

You could compute the coordinates I stashed in coordsN and coordsL when you draw your grid rather than hardcoding that information as data, or in if statements as in your original.