# w2tk.py
from Tkinter import *
root=Tk()
root.title('w2tk.py')
print 'w2tk.py connect points'
xp=[0 for i in range(100)]
yp=[0 for i in range(100)]
n=0
npoints=0

def redraw(): # because I am using c.delete(ALL)
  global c
  c.create_line( 20, 40, 20,350,fill='black')
  c.create_line( 20,350,380,350,fill='black')
  c.create_line(380,350,380, 40,fill='black')
  c.create_line(380, 40, 20, 40,fill='black')
  c.create_text( 200, 20, text='press button 1 for point. button 3 to connect',fill='black')
  c.create_text(200, 380, text='click here to exit', fill='black')


def mouseB1press(event): # left
  global xp, yp, n, npoints
  print 'mouse B1 press x=', event.x, ', y=', event.y
  if event.y>350:
    sys.exit()
  if event.y<40:
    return
  if n>0 :
    npoints=0
    n=0
    c.delete(ALL)
    redraw()
  x=event.x
  xp[npoints]=x
  y=event.y
  yp[npoints]=event.y
  c.create_oval(x-2,y-1,x+2,y+2,fill='red')
  npoints=npoints+1

def mouseB3press(event): # right
  global xp, yp, n, npoints
  print 'mouse B3 press '
  for i in range(npoints-1):  #connect every point to every other
    for j in range(npoints):
      c.create_line(xp[i], yp[i], xp[j], yp[j], fill='blue');
  n=npoints


c=Canvas(root, width=400, height=400, bg='white')

c.bind('<ButtonPress-1>'  , mouseB1press)
c.bind('<ButtonPress-3>'  , mouseB3press)
redraw()

c.pack()
root.mainloop()