import tkinter as tk

def cercle(x, y, r, coul='black'):
    """tracé d'un cercle de centre (x,y) et de rayon r"""
    can.create_oval(x-r, y-r, x+r, y+r, outline=coul)

def figure_1():
    """dessiner une cible"""
    #effacer l'ecran
    can.delete('all')

    #tracer les lignes verticales et horizontal :
    can.create_line(100, 0, 100, 200, fill='blue')
    can.create_line(0, 100, 200, 100, fill='blue')
    #tracer plusieurs cercles concentriques:
    rayon = 15
    while rayon < 100:
        cercle(100, 100, rayon)
        rayon+=15

def figure_2():
    """dessiner une visage simplifié"""
    #effacer l'ecran
    can.delete('all')
    #liste de propriété des cercles
    cc = [[100, 100, 80, 'red'],
    [70, 70, 15, 'blue'],
    [130, 70, 15, 'blue'],
    [70, 70, 5, 'black'],
    [130, 70, 5, 'black'],
    [44, 115, 20, 'red'],
    [156, 115, 20, 'red'],
    [100, 95, 15, 'purple'],
    [100, 145, 30, 'purple']]

    i=0
    for el in cc:
        cercle(el[0], el[1],  el[2], el[3])

#### programme principal ######
root=tk.Tk()
can=tk.Canvas(root, width=200, height=200, bg='ivory')
can.pack(side='top', padx=5, pady=5)

b1=tk.Button(root, text="dessin 1", command=figure_1)
b1.pack(side='left', padx=3, pady=3)

b2=tk.Button(root, text="dessin 2", command=figure_2)
b2.pack(side='right', padx=3, pady=3)

root.mainloop()