Question

I cannot run this code! Please explain and fix it for me

import turtle
import random

# Approximate size of turtle objects in pixels
BODY_SIZE = 80

# Half if the body size for collision detection with the edge of the screen
HALF_BODY_SIZE = BODY_SIZE / 2

# if enemies get this close to friend there is collision
COLLISION_DISTANCE = 5

# The window size
SIZE = 500

# inner boundary within window for reversing the direction of enemies
LOWER_BOUND = -SIZE / 2 + HALF_BODY_SIZE
UPPER_BOUND = SIZE / 2 - HALF_BODY_SIZE

# changing the turtle size
turtle.shapesize(3, 3)


# method to create and return a turtle
def createTurtle():
# creating a turtle
 t = turtle.Turtle()
# using circle shape and red color
 t.shape('circle')
 t.color('red')
# pen up
t.up()
# assigning a random direction as heading
t.setheading(random.randint(0, 360))
# returning it
    return t


# method to check if a turtle hit the edges
    def turtle_bounce(t):
        # finding position
        x, y = t.pos()
        # finding screen width and height
        width, height = t.getscreen().screensize()
        # checking if the coordinates are outside the bounds
        if x < -width / 2 or x > width / 2 or y < -height / 2 or y > height / 2:
            return True  # should bounce
            return False  # well inside

# creating a screen
win = turtle.Screen()
# adjusting animation delay and window update delay to make the drawings faster
# otherwise the animation will look pathetic.
# remove below two lines if you dont need.
win.delay(0)
win.tracer(2)
# 500x500 screen size
win.screensize(500, 500)
# adjusting screen coordinates
win.setworldcoordinates(-300, -250, 300, 250)
# adding title
win.title('Turtle Escape')

# creating a 'friend' turtle
friend = turtle.Turtle()
# using turtle shape and lime color
friend.shape('turtle')
friend.color('lime')
# pen up
friend.penup()
# set the position
friend.goto(win.window_width() / 2 - BODY_SIZE, - win.window_height() / 2 + BODY_SIZE)
friend.pendown()
# assigning a random direction as heading
friend.setheading(90)


def up():
    friend.penup()


# assigning a direction as heading
friend.setheading(90)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()


def down():
    friend.penup()


# assigning a direction as heading
friend.setheading(270)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()


def left():
    friend.penup()


# assigning a direction as heading
friend.setheading(180)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()


def right():
    friend.penup()


# assigning a direction as heading
friend.setheading(0)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()


def collision(friend, enemies):
# initialize is_collison to False
is_collision = False
        # for all enemies
    for enemy in enemies:
        # how far is this enemy from friend
        dist = friend.distance(enemy.pos())
        if (dist <= COLLISION_DISTANCE):
    is_collision = True  # set is_collision to true
    break  # break out of the loop, one collision is enough
    return is_collision  # return whether collision was detected


def reached_opposite_corner(friend):


# initialize reached_corner to False
    reached_corner = False
    x, y = friend.pos()
    if (x < LOWER_BOUND and y > UPPER_BOUND):
    # opposite corner when x< lowerbound and y > upper bounds
    # if friend's x is less that window's lower bounds
    # and friend's y is greater that upper bound
        reached_corner = True  # friend has reached corner set variable to true
        return reached_corner  # return whether friend has reached upper left corner or not

# creating an empty list of enemies
enemies = []
# looping for 5 times, creating a turtle, appending to list
for i in range(5):
    enemies.append(createTurtle())

# assigning functions to keys
win.onkey(up, "Up")
win.onkey(left, "Left")
win.onkey(right, "Right")
win.onkey(down, "Down")

# looping indefinitely
while True and not collision(friend, enemies) and not reached_opposite_corner(friend):
    # looping through each enemies
    for enemy in enemies:
        # moving forward 5 spaces
        enemy.forward(5)
        # fetching position
        x, y = enemy.pos()
        # checking if turtle hit the edges
        if turtle_bounce(enemy):
            # moving back
            enemy.backward(5)
            # using another random direction between 0 and 360
            enemy.setheading(random.randint(0, 360))

# Checking whether player won or not
if (reached_opposite_corner(friend)):
    print("Game over: your friend made it!")
else:
    print("Game over: your friend is now turtle soup!")

Answer 1

In case of any query do comment. Please rate answer as well. Thanks

Note: You have to make sure that indentation is correct. I have enabled the editor to show you white spaces as a difference. See below screen shots for difference. Code text is also provided.

Code:

import turtle
import random

# Approximate size of turtle objects in pixels
BODY_SIZE = 80

# Half if the body size for collision detection with the edge of the screen
HALF_BODY_SIZE = BODY_SIZE / 2

# if enemies get this close to friend there is collision
COLLISION_DISTANCE = 5

# The window size
SIZE = 500

# inner boundary within window for reversing the direction of enemies
LOWER_BOUND = -SIZE / 2 + HALF_BODY_SIZE
UPPER_BOUND = SIZE / 2 - HALF_BODY_SIZE

# changing the turtle size
turtle.shapesize(3, 3)

# method to create and return a turtle
def createTurtle():
# creating a turtle
t = turtle.Turtle()
# using circle shape and red color
t.shape('circle')
t.color('red')
# pen up
t.up()
# assigning a random direction as heading
t.setheading(random.randint(0, 360))
# returning it
return t

# method to check if a turtle hit the edges
def turtle_bounce(t):
# finding position
x, y = t.pos()
# finding screen width and height
width, height = t.getscreen().screensize()
# checking if the coordinates are outside the bounds
if x < -width / 2 or x > width / 2 or y < -height / 2 or y > height / 2:
return True # should bounce
return False # well inside

# creating a screen
win = turtle.Screen()
# adjusting animation delay and window update delay to make the drawings faster
# otherwise the animation will look pathetic.
# remove below two lines if you dont need.
win.delay(0)
win.tracer(2)
# 500x500 screen size
win.screensize(500, 500)
# adjusting screen coordinates
win.setworldcoordinates(-300, -250, 300, 250)
# adding title
win.title('Turtle Escape')

# creating a 'friend' turtle
friend = turtle.Turtle()
# using turtle shape and lime color
friend.shape('turtle')
friend.color('lime')
# pen up
friend.penup()
# set the position
friend.goto(win.window_width() / 2 - BODY_SIZE, - win.window_height() / 2 + BODY_SIZE)
friend.pendown()
# assigning a random direction as heading
friend.setheading(90)

def up():
friend.penup()
# assigning a direction as heading
friend.setheading(90)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()

def down():
friend.penup()
# assigning a direction as heading
friend.setheading(270)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()

def left():
friend.penup()
# assigning a direction as heading
friend.setheading(180)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()

def right():
friend.penup()
# assigning a direction as heading
friend.setheading(0)
# moving forward 45 spaces
friend.forward(45)
friend.pendown()

def collision(friend, enemies):
# initialize is_collison to False
is_collision = False
# for all enemies
for enemy in enemies:
# how far is this enemy from friend
dist = friend.distance(enemy.pos())
if (dist <= COLLISION_DISTANCE):
is_collision = True # set is_collision to true
break # break out of the loop, one collision is enough
return is_collision # return whether collision was detected

def reached_opposite_corner(friend):

# initialize reached_corner to False
reached_corner = False
x, y = friend.pos()
if (x < LOWER_BOUND and y > UPPER_BOUND):
# opposite corner when x< lowerbound and y > upper bounds
# if friend's x is less that window's lower bounds
# and friend's y is greater that upper bound
reached_corner = True # friend has reached corner set variable to true
return reached_corner # return whether friend has reached upper left corner or not

# creating an empty list of enemies
enemies = []
# looping for 5 times, creating a turtle, appending to list
for i in range(5):
enemies.append(createTurtle())

# assigning functions to keys
win.onkey(up, "Up")
win.onkey(left, "Left")
win.onkey(right, "Right")
win.onkey(down, "Down")
win.listen()

# looping indefinitely
while True and not collision(friend, enemies) and not reached_opposite_corner(friend):
# looping through each enemies
for enemy in enemies:
# moving forward 5 spaces
enemy.forward(5)
# fetching position
x, y = enemy.pos()
# checking if turtle hit the edges
if turtle_bounce(enemy):
# moving back
enemy.backward(5)
# using another random direction between 0 and 360
enemy.setheading(random.randint(0, 360))

# Checking whether player won or not
if (reached_opposite_corner(friend)):
print("Game over: your friend made it!")
else:
print("Game over: your friend is now turtle soup!")

================screen shot of the code for indentation=======

Output: