Re: Tkinter update
Fri, 03 Jun 1994 16:13:28 +0200

Well folks, it's been a pleasant day toying around with Steen
Lumholt's Tk-for-Python module. I thought I'd show you my first
complete program: the "dialog" example procedure from Ousterhout's
book translated into Python.

Comparing the Python code to the Tcl version, the most blatant
difference is the many Pack.config() calls needed to emulate a single
'pack configure' call. I think a streamlined interface for this is
needed, e.g.

w.pack({'side': 'left', 'expand': 1})

Likewise for 'wm', 'raise' and possibly other Tcl procedures that have
widget arguments. But is a good start already!

(Two more remarks on Tkinter: (1) The defaulting of screenName to
$DISPLAY or ':0' is unnecessary, the Tk library does this (except
':0', which isn't standard X11 policy anyway). (2) I would like
w.cmd(...) to return the return value of -- this is
sometimes useful.

Here's my file:

# A Python function that generates dialog boxes with a text message,
# optional bitmap, and any number of buttons.
# Cf. Ousterhout, Tcl and the Tk Toolkit, Figs. 27.2-3, pp. 269-270.

from Tkinter import *

# (This is missing in the distributed Tkinter)
class Message(Widget):
def __init__(self, master=None, cnf={}):
Widget.__init__(self, master, 'message', cnf)

def dialog(master, title, text, bitmap, default, *args):

# 1. Create the top-level window and divide it into top
# and bottom parts.

w = Toplevel(master, {'class': 'Dialog'})'global', 'button')
top = Frame(w, {'relief': 'raised', 'bd': 1})
Pack.config(top, 'side', 'top')
Pack.config(top, 'fill', 'both')
bot = Frame(w, {'relief': 'raised', 'bd': 1})
Pack.config(bot, 'side', 'bottom')
Pack.config(bot, 'fill', 'both')

# 2. Fill the top part with the bitmap and message.

msg = Message(top,
{'width': '3i',
'text': text,
Pack.config(msg, 'side', 'right')
Pack.config(msg, 'expand', 1)
Pack.config(msg, 'fill', 'both')
Pack.config(msg, 'padx', '3m')
Pack.config(msg, 'pady', '3m')
if bitmap:
bm = Label(top, {'bitmap': bitmap})
Pack.config(bm, 'side', 'left')
Pack.config(bm, 'padx', '3m')
Pack.config(bm, 'pady', '3m')

# 3. Create a row of buttons at the bottom of the dialog.

buttons = []
i = 0
for but in args:
b = Button(bot, {'text': but,
'command': ('set', 'button', i)})
if i == default:
bd = Frame(bot, {'relief': 'sunken', 'bd': 1})'raise', b)
Pack.config(bd, 'side', 'left')
Pack.config(bd, 'expand', 1)
Pack.config(bd, 'padx', '3m')
Pack.config(bd, 'pady', '2m')
Pack.config(b, 'in', bd)
Pack.config(b, 'side', 'left')
Pack.config(b, 'padx', '2m')
Pack.config(b, 'pady', '2m')
Pack.config(b, 'ipadx', '2m')
Pack.config(b, 'ipady', '1m')
Pack.config(b, 'side', 'left')
Pack.config(b, 'expand', 1)
Pack.config(b, 'padx', '3m')
Pack.config(b, 'pady', '3m')
Pack.config(b, 'ipady', '2m')
Pack.config(b, 'ipady', '1m')
i = i+1

# 4. Set up a binding for <Return>, if there's a default,
# set a grab, and claim the focus too.

if default >= 0:
lambda b=buttons[default], i=default:
(b.cmd('flash'),'set', 'button', i)))

oldFocus ='focus')'grab', 'set', w)'focus', w)

# 5. Wait for the user to respond, then restore the focus
# and return the index of the selected button.'tkwait', 'variable', 'button')'destroy', w)'focus', oldFocus)
return'set', 'button')

# The rest is the test program.

def go():
i = dialog(mainWidget,
'Not Responding',
"The file server isn't responding right now; "
"I'll keep trying.",
print 'pressed button', i
i = dialog(mainWidget,
'File Modified',
'File "tcl.h" has been modified since '
'the last time it was saved. '
'Do you want to save it before exiting the application?',
'Save File',
'Discard Changes',
'Return To Editor')
print 'pressed button', i

def test():
global mainWidget
mainWidget = Frame()
start = Button(mainWidget, {'text': 'Press Here To Start'})
start['command'] = go

if __name__ == '__main__':

--Guido van Rossum, CWI, Amsterdam <>
URL: <>