python script for simple GUI design with tkinter

Simple_gui_example

from tkinter import *
from random import randrange
def drawshape():
    x1,x2,x3=150,400,250
    y1,y2,y3=250,150,350
    can1.create_line(y2,x3,y3,x3,width=2,fill=coul)
    can1.create_line(y1,x1,y1,x2,width=2,fill=coul)
def change_shape_colour():
    global coul
    pal=['purple','red','blue','orange','yellow']
    c=randrange(4)
    coul=pal[c]
    drawshape()
coul='dark green'

fen1=Tk()
can1=Canvas(fen1,bg='dark grey',height=500,width=500)
can1.pack(side=LEFT)
bou1=Button(fen1,text='Quitter',command=fen1.quit)
bou1.pack(side=BOTTOM)
bou2=Button(fen1,text='Draw a shape',command=drawshape)
bou2.pack()
bou3=Button(fen1,text='Change color',command=change_shape_colour)
bou3.pack()
fen1.mainloop()