import turtle

def draw_square(x, y):

   turtle.penup()

   turtle.goto(x, y)

   turtle.pendown()

   for i in range(4):

       turtle.forward(100)

       turtle.right(50)

turtle.setup(600, 400)

turtle.title("Рисуем  мышкой")

turtle.shape("turtle")

turtle.pensize(3)

turtle.onscreenclick(draw_square)

turtle.mainloop()