from turtle import *
from random import randint

def add_circles(number):
    """ Add number colored circles of radius 4 randomly through the screen """
    x_range = int( window_width()/2 )
    y_range = int( window_height()/2 )
    
    for i in range(number):
        x = randint(-x_range, x_range)
        y = randint(-y_range, y_range)
        
        # set the fill color of the circles
        setcolor_xy(x, y)
            
        pu()
        goto(x,y)
        pd()        
        begin_fill()
        circle(8)
        end_fill()

def setcolor_xy(x, y):
    """ Set the fill color based on x, y coordinates """
    if x < 0 and y < 0:
        fillcolor("blue")
    elif x < 0 and y > 0:
        fillcolor("purple")
    elif x > 0 and y < 0:
        fillcolor("red")
    else:
        fillcolor("yellow")        
         
def setcolor_random():
    """ Set the fill color randomly from: blue, purple, red and yellow """
    color = randint(1,4)
    
    if color == 1:
        fillcolor("blue")
    elif color == 2:
        fillcolor("purple")
    elif color == 3:
        fillcolor("red")
    else: # color == 4
        fillcolor("yellow")