Syntax Error with = sign and more

[Kathleen57]

Hi,
I'm using the book Coding Projects in Python to (slowly) learn Python. This exercise is to program the turtle to draw multiple colored lines on the screen. Here is the entire program code: (when I posted it, all the indents disappeared; I do have indents in mine):

import random
import turtle as t

def get_line_length():
    choice = input('Enter line length (long, medium, short):')
    if choice == 'long':
        line_length=250
    elif choice == 'medium':
        line_length=200
    else:
        line_length=100
    return line_length

def get_line_width():
    choice = input('Enter line width (superthick, thick, thin): ')
    if choice == 'superthick':
        line_width-40
    elif choice == 'thick':
        line_width=25
    else:
        line_width=10
    return line_width

def inside_window():
    left_limit = (-t.window_width() / 2) + 100
    right_limit = (t.window_width() / 2) - 100
    top_limit = (t.window_height() / 2) - 100
    bottom_limit = (t.window_height() / 2 + 100
    (x,y) = t.position()
    inside = left_limit < x < right_limit and bottom_limit < y < top_limit
    return inside  
    
def move_turtle(line_length):
    pen_colors = ['red', 'orange', 'yellow', 'blue', 'green', 'purple']
    t.pencolor(random.choice(pen_colors))
    if inside_window():
        angle = random.randint(0, 180)
        t.right(angle)
        t.forward(line_length)
    else:
        t.backward(line_length)

line_length=get_line_length()
line_width=get_line_width()

t.shape('turtle')
t.fillcolor('green')
t.bgcolor('black')
t.speed('fastest')
t.pensize(line_width)

while True:
    move_turtle(line_length)

My first syntax error is the equal sign on the 6th line down - (x,y) = t.position().

def inside_window():
    left_limit = (-t.window_width() / 2) + 100
    right_limit = (t.window_width() / 2) - 100
    top_limit = (t.window_height() / 2) - 100
    bottom_limit = (t.window_height() / 2 + 100
    (x,y) = t.position()
    inside = left_limit < x < right_limit and bottom_limit < y < top_limit
    return inside

In trying to figure it out, I changed that = sign to the double ==. Even though that probably would not help the program, the checker accepted it and moved forward. But the next syntax error is the word "inside" on the 7th line: inside = left_limit < x < right_limit and bottom_limit < y < top_limit.

I appreciate any help! Thank you.