import turtle
import atexit

x1 = 0
y1 = 0
x2 = 0
y2 = 0 
click = 0

f = open("demofile.py", "w")
f.write("import turtle\n")
def insertloop():
 f.write("turtle.mainloop()\n")

atexit.register(insertloop)

def func_on_screen(x, y):
 global x1
 global y1
 global x2
 global y2
 global click 
 global f
 if click == 0:
  x1 = x
  y1 = y
  print ("click 1")
  print (x1,y1)
  f.write(f"turtle.goto({x1},{y1})\n")
 if click == 1:
  x2 = x
  y2 = y
  
  print ("click 2")
  print (x2,y2)
  f.write(f"turtle.goto({x2},{y2})\n")
  
  draw_line(x1,y1,y2,x2)
 
 click = click + 1
 if click == 2:
  click = 0
def draw_line(x1,y1,y2,x2):
 turtle.goto(x1,y1)
 turtle.goto(x2,y2)

turtle.onscreenclick(func_on_screen)
turtle.mainloop()