Python, Tkinter: How do I
determine if a window has been
resized? I want to locate
buttons vertically along the
right border and need to know
the new width. The buttons are
to move with the change of
location of the right-side
border.







SGA

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-02-24 01:14, Steve GS via Python-list wrote:

Python, Tkinter: How do I
determine if a window has been
resized? I want to locate
buttons vertically along the
right border and need to know
the new width. The buttons are
to move with the change of
location of the right-side
border.

Bind an event handler for '<Configure>':

----8<----

import tkinter as tk

def on_configure(*args):
print(args)

root = tk.Tk()
root.bind('<Configure>', on_configure)
root.mainloop()

----8<----

Are you placing the buttons yourself? I always use layouts and they
handle such things automatically.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

How do I extract the values
from args?

SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of MRAB via Python-list
Sent: Friday, February 23,
2024 9:27 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2024-02-24 01:14, Steve GS
via Python-list wrote:

Python, Tkinter: How do I
determine if a window has

been

resized? I want to locate
buttons vertically along the
right border and need to

know

the new width. The buttons

are

to move with the change of
location of the right-side
border.

Bind an event handler for
'<Configure>':

----8<----

import tkinter as tk

def on_configure(*args):
print(args)

root = tk.Tk()
root.bind('<Configure>',
on_configure)
root.mainloop()

----8<----

Are you placing the buttons
yourself? I always use layouts
and they handle such things
automatically.

--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 24 Feb 2024, at 04:36, Steve GS via Python-list <python-list@python.org> wrote:

How do I extract the values
from args?

You can look up the args in documentation.
You can run the example code MRAB provided and see what is printed to learn what is in the args.

Barry

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Yes, I ran that elegantly
simple code. The print
statement reports the X, Y,
Height and Width values.
However, I do not see how to
capture the width value.

I experimented with the code
Vwidth = rootV.winfo_width()
and it also reports the width
as I resize the window.

However, I cannot seem to use
the variable Vwidth outside
the sub routine. It is acting
as if Vwidth is not global but
I added that. It is reported
that Vwidth is not defined
when I try to use it in my
code.

So close......
SGA

-----Original Message-----
From: Barry
<barry@barrys-emacs.org>
Sent: Saturday, February 24,
2024 3:04 AM
To: Steve GS
<Gronicus@sga.ninja>
Cc: MRAB
<python@mrabarnett.plus.com>;
python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 24 Feb 2024, at 04:36,

Steve GS via Python-list
<python-list@python.org>
wrote:

How do I extract the values
from args?

You can look up the args in
documentation.
You can run the example code
MRAB provided and see what is
printed to learn what is in
the args.

Barry

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

"Steve GS" <Gronicus@SGA.Ninja> writes:

width

Using a geometry manager, such as "pack", you usually do not need
to know when a window has been resized or to know that width.

You need to read a good tkinter book and learn about:

tkinter.Tk
pack
tkinter.Frame
side=tkinter.LEFT
side=tkinter.RIGHT
expand=tkinter.YES
fill=tkinter.X
fill=tkinter.Y
fill=tkinter.BOTH

. I'd recommand the GUI part of "Programming Python" by Mark Lutz!

The geometry manages "pack" and "grid" should be able
to handle 99 percent of all GUI geometry requirements,
so you would need a good reason not to use them.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2/24/2024 3:20 AM, Steve GS via Python-list wrote:

Yes, I ran that elegantly
simple code. The print
statement reports the X, Y,
Height and Width values.
However, I do not see how to
capture the width value.

I experimented with the code
Vwidth = rootV.winfo_width()
and it also reports the width
as I resize the window.

However, I cannot seem to use
the variable Vwidth outside
the sub routine. It is acting
as if Vwidth is not global but
I added that. It is reported
that Vwidth is not defined
when I try to use it in my
code.

Well, yes, in Python a variable created inside a function or method is
local to that function unless you declare it global. That characteristic
is called its "scope". But if you think you need it to be a global
variable you should rethink your design. For one thing, before the next
time you use your global variable the window size may have changed again.

Instead, it would be better to have the function that responds to the
resize event perform the action that you want, or call another function
that does, passing the new width to it.

Note that in most programming languages, variables have a scope. The
rules about those scopes vary between languages.

So close......
SGA

-----Original Message-----
From: Barry
<barry@barrys-emacs.org>
Sent: Saturday, February 24,
2024 3:04 AM
To: Steve GS
<Gronicus@sga.ninja>
Cc: MRAB
<python@mrabarnett.plus.com>;
python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 24 Feb 2024, at 04:36,

Steve GS via Python-list
<python-list@python.org>
wrote:

How do I extract the values
from args?

You can look up the args in
documentation.
You can run the example code
MRAB provided and see what is
printed to learn what is in
the args.

Barry

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Thomas Passin <list1@tompassin.net> writes:

Well, yes, in Python a variable created inside a function or method is
local to that function unless you declare it global.

Or equivalent,

main.py

def f():
globals()[ 'x' ]= 2 # not a declaration!

f()

print( x )

_sys.stderr

2

But if you think you need it to be a global variable you
should rethink your design.

"Global" variables in Python are actually just "module variable".
Module variables are not so bad. If you think of the module as a
singleton object it's kinda like a class.

But the usual recommendation is to use a class. I.e., transform

main.py

def write_global():
globals()[ 'x' ]= 2

def read_global():
print( globals()[ 'x' ])

write_global()
read_global()

_sys.stderr

2

into

class Object_:
def write_field( self ):
self.x = 2
def read_field( self ):
print( self.x )

object_ = Object_()
object_.write_field()
object_.read_field()

_sys.stderr

2

For one thing, before the next time you use your global
variable the window size may have changed again.

The OP might be sleep walking into writing his own ad hoc,
informally-specified, bug-ridden, slow implementation of
half of a geometry manager like "pack" or "grid".

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-02-25 00:33, Steve GS via Python-list wrote:

"Well, yes, in Python a
variable created inside a
function or method is local to
that function unless you
declare it global."

Yes, I knew that. I tried to
global it both before the
function call and within it.
Same for when I created the
variable. If I try to use it
in the rest of the code, it
keeps coming up as not
declared. In other functions,
I can 'return' the variable
but that apparently would not
work for this function.

Is this type of function any
different that that which I
have been using?

Please post a short example that shows the problem.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

"Well, yes, in Python a
variable created inside a
function or method is local to
that function unless you
declare it global."

Yes, I knew that. I tried to
global it both before the
function call and within it.
Same for when I created the
variable. If I try to use it
in the rest of the code, it
keeps coming up as not
declared. In other functions,
I can 'return' the variable
but that apparently would not
work for this function.

Is this type of function any
different that that which I
have been using?

SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of Thomas Passin via
Python-list
Sent: Saturday, February 24,
2024 8:40 AM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2/24/2024 3:20 AM, Steve GS
via Python-list wrote:

Yes, I ran that elegantly
simple code. The print
statement reports the X, Y,
Height and Width values.
However, I do not see how to
capture the width value.

I experimented with the

code

Vwidth = rootV.winfo_width()
and it also reports the

width

as I resize the window.

However, I cannot seem to

use

the variable Vwidth outside
the sub routine. It is

acting

as if Vwidth is not global

but

I added that. It is

reported

that Vwidth is not defined
when I try to use it in my
code.

Well, yes, in Python a
variable created inside a
function or method is local to
that function unless you
declare it global. That
characteristic is called its
"scope". But if you think you
need it to be a global
variable you should rethink
your design. For one thing,
before the next time you use
your global variable the
window size may have changed
again.

Instead, it would be better to
have the function that
responds to the resize event
perform the action that you
want, or call another function
that does, passing the new
width to it.

Note that in most programming
languages, variables have a
scope. The rules about those
scopes vary between languages.

So close......
SGA

-----Original Message-----
From: Barry
<barry@barrys-emacs.org>
Sent: Saturday, February 24,
2024 3:04 AM
To: Steve GS
<Gronicus@sga.ninja>
Cc: MRAB

<python@mrabarnett.plus.com>;

python-list@python.org
Subject: Re: Problem

resizing

a window and button

placement

On 24 Feb 2024, at 04:36,

Steve GS via Python-list
<python-list@python.org>
wrote:

How do I extract the values
from args?

You can look up the args in
documentation.
You can run the example code
MRAB provided and see what

is

printed to learn what is in
the args.

Barry

--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

import tkinter as tk

#global Ww Neither global
helps
def on_configure(*args):
# print(args)
#global Ww Neither
global helps
Ww = root.winfo_width()
print("WwInside = <" +
str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>',
on_configure)
print("WwOutside = <" +
str(Ww) + ">")
#NameError: name 'Ww' is not
defined
root.mainloop()

SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of MRAB via Python-list
Sent: Saturday, February 24,
2024 7:49 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2024-02-25 00:33, Steve GS
via Python-list wrote:

"Well, yes, in Python a
variable created inside a
function or method is local

to

that function unless you
declare it global."

Yes, I knew that. I tried to
global it both before the
function call and within it.
Same for when I created the
variable. If I try to use it
in the rest of the code, it
keeps coming up as not
declared. In other

functions,

I can 'return' the variable
but that apparently would

not

work for this function.

Is this type of function any
different that that which I
have been using?

Please post a short example
that shows the problem.

--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-02-25 02:51, Steve GS wrote:

import tkinter as tk

#global Ww Neither global helps
def on_configure(*args):
# print(args)
#global Ww Neither global helps
Ww = root.winfo_width()
print("WwInside = <" + str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>', on_configure)
print("WwOutside = <" + str(Ww) + ">")
#NameError: name 'Ww' is not defined
root.mainloop()

'Ww' won't exist until 'on_configure' assigns to it, and that won't
happen until `mainloop` starts.

Also, 'global' works only within a function.

----8<----

import tkinter as tk

def on_configure(event):
    print(f'{event.width=}, {event.height=}')

root = tk.Tk()
root.bind('<Configure>',on_configure)
root.mainloop()

----8<----

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

So, how do I use the width value in my code?

SGA

-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja@python.org> On Behalf Of MRAB via Python-list
Sent: Saturday, February 24, 2024 10:36 PM
To: python-list@python.org
Subject: Re: Problem resizing a window and button placement

On 2024-02-25 02:51, Steve GS wrote:

import tkinter as tk

#global Ww Neither global helps
def on_configure(*args):
# print(args)
#global Ww Neither global helps
Ww = root.winfo_width()
print("WwInside = <" + str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>', on_configure) print("WwOutside = <" + str(Ww)
+ ">")
#NameError: name 'Ww' is not defined
root.mainloop()

'Ww' won't exist until 'on_configure' assigns to it, and that won't happen until `mainloop` starts.

Also, 'global' works only within a function.

----8<----

import tkinter as tk

def on_configure(event):
print(f'{event.width=}, {event.height=}')

root = tk.Tk()
root.bind('<Configure>',on_configure)
root.mainloop()

----8<----

--
https://mail.python.org/mailman/listinfo/python-list

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2/24/2024 9:51 PM, Steve GS via Python-list wrote:
First of all, please make sure that the formatting is readable and
especially the indentation. This is Python, after all.

Do not use tabs; use 3 or 4 spaces instead of each tab.

import tkinter as tk

#global Ww Neither global
helps
def on_configure(*args):
# print(args)
#global Ww Neither
global helps
Ww = root.winfo_width()
print("WwInside = <" +
str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>',
on_configure)
print("WwOutside = <" +
str(Ww) + ">")
#NameError: name 'Ww' is not
defined

The function that declares Ww hasn't run yet. As I wrote earlier, the
function bound to the callback should do all the work for the callback,
or it should call other functions that do. That's if you don't let a
layout do it all for you, as others have written.

root.mainloop()

SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of MRAB via Python-list
Sent: Saturday, February 24,
2024 7:49 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2024-02-25 00:33, Steve GS
via Python-list wrote:

"Well, yes, in Python a
variable created inside a
function or method is local

to

that function unless you
declare it global."

Yes, I knew that. I tried to
global it both before the
function call and within it.
Same for when I created the
variable. If I try to use it
in the rest of the code, it
keeps coming up as not
declared. In other

functions,

I can 'return' the variable
but that apparently would

not

work for this function.

Is this type of function any
different that that which I
have been using?

Please post a short example
that shows the problem.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

The print statement in the
function prints.
Does that not mean that the
function is being called?



SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of Thomas Passin via
Python-list
Sent: Saturday, February 24,
2024 10:39 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2/24/2024 9:51 PM, Steve GS
via Python-list wrote:
First of all, please make sure
that the formatting is
readable and especially the
indentation. This is Python,
after all.

Do not use tabs; use 3 or 4
spaces instead of each tab.

import tkinter as tk

#global Ww Neither global
helps
def on_configure(*args):
# print(args)
#global Ww Neither
global helps
Ww =

root.winfo_width()

print("WwInside = <" +
str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>',
on_configure)
print("WwOutside = <" +
str(Ww) + ">")
#NameError: name 'Ww' is not
defined

The function that declares Ww
hasn't run yet. As I wrote
earlier, the function bound to
the callback should do all the
work for the callback, or it
should call other functions
that do. That's if you don't
let a layout do it all for
you, as others have written.

root.mainloop()

SGA

-----Original Message-----
From: Python-list

<python-list-bounces+gronicus=

sga.ninja@python.org> On
Behalf Of MRAB via

Python-list

Sent: Saturday, February 24,
2024 7:49 PM
To: python-list@python.org
Subject: Re: Problem

resizing

a window and button

placement

On 2024-02-25 00:33, Steve

GS

via Python-list wrote:

"Well, yes, in Python a
variable created inside a
function or method is local

to

that function unless you
declare it global."

Yes, I knew that. I tried

to

global it both before the
function call and within

it.

Same for when I created the
variable. If I try to use

it

in the rest of the code, it
keeps coming up as not
declared. In other

functions,

I can 'return' the variable
but that apparently would

not

work for this function.

Is this type of function

any

different that that which I
have been using?

Please post a short example
that shows the problem.

--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

SOLUTION FOUND!

The fix was to write the code that uses the width value and to place it into the function itself.
Kluge? Maybe but it works.

Mischief Managed.

========================
As for the most recent suggestion, it fails for me:

Traceback (most recent call last):
File "F:/___zInsulin Code A 08-02-23/WinPic/IOWw.pyw", line 14, in <module>
print("Ww Outside = <" + str(Ww) > + ">")
TypeError: bad operand type for unary +: 'str'

With the need to close the window, it adds an extra step and intervention to the program to use. I am not sure how this help[s.

As a curio, it would be interesting to see how to use the value of a variable, created in the function used here, and make it available to the code outside the function.



SGA

-----Original Message-----
From: Alan Gauld <learn2program@gmail.com>
Sent: Sunday, February 25, 2024 12:44 PM
To: Steve GS <Gronicus@SGA.Ninja>; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement

On 25/02/2024 03:58, Steve GS via Python-list wrote:
import tkinter as tk

Ww = None

def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside = <" + str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>', on_configure)
root.mainloop()

print("Ww Outside = <" + str(Ww) > + ">")

Produces:
Ww Inside = <200>
Ww Inside = <200>
Ww Inside = <205>
Ww Inside = <205>
Ww Inside = <206>
Ww Inside = <206>
Ww Outside = <206>

HTH

--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2/25/2024 4:19 PM, Steve GS via Python-list wrote:

SOLUTION FOUND!

The fix was to write the code that uses the width value and to place it into the function itself.
Kluge? Maybe but it works.

Right, just what I wrote earlier:

"have the function that responds to the resize event perform the action
that you want"

Mischief Managed.

========================
As for the most recent suggestion, it fails for me:

Traceback (most recent call last):
File "F:/___zInsulin Code A 08-02-23/WinPic/IOWw.pyw", line 14, in <module>
print("Ww Outside = <" + str(Ww) > + ">")
TypeError: bad operand type for unary +: 'str'

With the need to close the window, it adds an extra step and intervention to the program to use. I am not sure how this help[s.

As a curio, it would be interesting to see how to use the value of a variable, created in the function used here, and make it available to the code outside the function.

SGA

-----Original Message-----
From: Alan Gauld <learn2program@gmail.com>
Sent: Sunday, February 25, 2024 12:44 PM
To: Steve GS <Gronicus@SGA.Ninja>; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement

On 25/02/2024 03:58, Steve GS via Python-list wrote:
import tkinter as tk

Ww = None

def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside = <" + str(Ww) + ">")

root = tk.Tk()
root.bind('<Configure>', on_configure)
root.mainloop()

print("Ww Outside = <" + str(Ww) > + ">")

Produces:
Ww Inside = <200>
Ww Inside = <200>
Ww Inside = <205>
Ww Inside = <205>
Ww Inside = <206>
Ww Inside = <206>
Ww Outside = <206>

HTH

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-02-25 21:19, Steve GS via Python-list wrote:

SOLUTION FOUND!

The fix was to write the code that uses the width value and to place it into the function itself.
Kluge? Maybe but it works.

Mischief Managed.

========================
As for the most recent suggestion, it fails for me:

Traceback (most recent call last):
File "F:/___zInsulin Code A 08-02-23/WinPic/IOWw.pyw", line 14, in <module>
print("Ww Outside = <" + str(Ww) > + ">")
TypeError: bad operand type for unary +: 'str'

It fails because there's a mistake. It should be:

print("Ww Outside = <" + str(Ww) + ">")

With the need to close the window, it adds an extra step and intervention to the program to use. I am not sure how this help[s.

As a curio, it would be interesting to see how to use the value of a variable, created in the function used here, and make it available to the code outside the function.

[snip]

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Ww Inside = <250>
Ww Inside = <249>
Ww Inside = <250>
Ww Outside =
<1770662408256on_configure>

Here is my result...

SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of MRAB via Python-list
Sent: Sunday, February 25,
2024 6:40 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2024-02-25 21:19, Steve GS
via Python-list wrote:

SOLUTION FOUND!

The fix was to write the

code that uses the width value
and to place it into the
function itself.

Kluge? Maybe but it works.

Mischief Managed.

========================
As for the most recent

suggestion, it fails for me:

Traceback (most recent call

last):

File "F:/___zInsulin Code

A 08-02-23/WinPic/IOWw.pyw",
line 14, in <module>

print("Ww Outside = <"

+ str(Ww) > + ">")

TypeError: bad operand type

for unary +: 'str'

It fails because there's a
mistake. It should be:

print("Ww Outside = <" +
str(Ww) + ">")

With the need to close the

window, it adds an extra step
and intervention to the
program to use. I am not sure
how this help[s.

As a curio, it would be

interesting to see how to use
the value of a variable,
created in the function used
here, and make it available to
the code outside the function.

[snip]


--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
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Although your code produces the value of Ww outside the function, I do not see how I can use the value of Ww unless I close the program.

import tkinter as tk

Ww = None # What does this do? Why not Integer?
WwZ = None

def on_configure(*args):
global Ww
global WwZ
Ww = root.winfo_width()
print("9 Ww Inside =<"+str(Ww)+">") # works
WwZ = Ww * 2
print("11 WwZ Inside =<"+str(WwZ)+">") # works
return(Ww) #Can I use this?

root = tk.Tk()
root.bind('<Configure>',on_configure)
print("15 Ww Inside1 = <"+str(Ww)+">")
#Ww2 = int(Ww) * 2 # fails
print("17 WwZ Inside2 = <"+str(WwZ)+">")

root.mainloop()

Ww2 = int(Ww) * 2 #Works but only after the program stops
print("21 Ww Outside2 = <"+str(WwZ)+">")
# Can I have concentric loops?


SGA

-----Original Message-----
From: Alan Gauld <learn2program@gmail.com>
Sent: Monday, February 26, 2024 4:04 AM
To: Steve GS <Gronicus@SGA.Ninja>; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement

On 26/02/2024 07:56, Steve GS via Python-list wrote:

Then there is that discovery
element: Why is my original
idea not working? I still
cannot pass the value back
from the function. What is
different about this function
that others would have given
me the value?

There is nothing different, see the code below.
print() is a function like any other.
In this case it is called after you close the window, ie after mainloop() exits.
But any other function called inside
mainloop - eg any other event handler can also access it.

For example, if you added a button:

def printW(): print("Button Ww = ", Ww)

bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()

You would be able to print the value on demand.

import tkinter as tk

Ww = None

def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside =<"+str(Ww)+">")

root = tk.Tk()
root.bind('<Configure>',on_configure)
root.mainloop()

print("Ww Outside = <"+str(Ww)+">")

--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2/26/2024 6:02 AM, Steve GS via Python-list wrote:

Although your code produces the value of Ww outside the function, I do not see how I can use the value of Ww unless I close the program.

The configuration event hasn't fired at the time you include the print statement in the handler's def block, and therefore the print function
inside your handler hasn't invoked. It won't be invoked until you
resize the window.

There is no point to saving the width and height outside your
on_configure() function, because outside that function you can't know if
they have been changed. There could even have been a race condition
where you use one but the other changes before you get around to using
it. It's better just to ask tk for the values whenever you need them,
as you do inside your handler.

import tkinter as tk

Ww = None # What does this do? Why not Integer?
WwZ = None

# These could be integers, like 0, but that would not be the correct
# window sizes at that point. The window is either not constructed or it
# has some definite size that is not zero.

def on_configure(*args):
global Ww
global WwZ
Ww = root.winfo_width()
print("9 Ww Inside =<"+str(Ww)+">") # works
WwZ = Ww * 2
print("11 WwZ Inside =<"+str(WwZ)+">") # works
return(Ww) #Can I use this?

root = tk.Tk()
root.bind('<Configure>',on_configure)
print("15 Ww Inside1 = <"+str(Ww)+">")
#Ww2 = int(Ww) * 2 # fails
print("17 WwZ Inside2 = <"+str(WwZ)+">")

root.mainloop()

Ww2 = int(Ww) * 2 #Works but only after the program stops
print("21 Ww Outside2 = <"+str(WwZ)+">")
# Can I have concentric loops?

SGA

-----Original Message-----
From: Alan Gauld <learn2program@gmail.com>
Sent: Monday, February 26, 2024 4:04 AM
To: Steve GS <Gronicus@SGA.Ninja>; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement

On 26/02/2024 07:56, Steve GS via Python-list wrote:

Then there is that discovery
element: Why is my original
idea not working? I still
cannot pass the value back
from the function. What is
different about this function
that others would have given
me the value?

There is nothing different, see the code below.
print() is a function like any other.
In this case it is called after you close the window, ie after mainloop() exits.
But any other function called inside
mainloop - eg any other event handler can also access it.

For example, if you added a button:

def printW(): print("Button Ww = ", Ww)

bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()

You would be able to print the value on demand.

import tkinter as tk

Ww = None

def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside =<"+str(Ww)+">")

root = tk.Tk()
root.bind('<Configure>',on_configure)
root.mainloop()

print("Ww Outside = <"+str(Ww)+">")

--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

The configuration event

hasn't fired at the time you
include the print statement in
the handler's def block, and
therefore the print function
inside your handler hasn't
invoked. It won't be invoked
until you resize the window.

Exactly....

There is no point (really?)

to saving the width and height
outside your
on_configure() function,
because outside that function
you can't know if they have
been changed. There could
even have been a race
condition where you use one
but the other changes before
you get around to using it.

Aside from using it to resized
the window, is there no way to
know the last value of the
change for use in the program?
I could write the value to a
label and read it back later
in the process but that sounds
to be klugy.

It's better just to ask tk

for the values whenever you
need them, as you do inside
your handler.

How would that be done?



SGA

-----Original Message-----
From: Python-list
<python-list-bounces+gronicus=
sga.ninja@python.org> On
Behalf Of Thomas Passin via
Python-list
Sent: Monday, February 26,
2024 8:34 AM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement

On 2/26/2024 6:02 AM, Steve GS
via Python-list wrote:

Although your code produces

the value of Ww outside the
function, I do not see how I
can use the value of Ww unless
I close the program.

The configuration event hasn't
fired at the time you include
the print statement in the
handler's def block, and
therefore the print function
inside your handler hasn't
invoked. It won't be invoked
until you resize the window.

There is no point to saving
the width and height outside
your
on_configure() function,
because outside that function
you can't know if they have
been changed. There could
even have been a race
condition where you use one
but the other changes before
you get around to using it.
It's better just to ask tk for
the values whenever you need
them, as you do inside your
handler.

import tkinter as tk

Ww = None # What does this

do? Why not Integer?

WwZ = None

# These could be integers,
like 0, but that would not be
the correct # window sizes at
that point. The window is
either not constructed or it #
has some definite size that is
not zero.

def on_configure(*args):
global Ww
global WwZ
Ww =

root.winfo_width()

print("9 Ww Inside

=<"+str(Ww)+">") # works

WwZ = Ww * 2
print("11 WwZ

Inside =<"+str(WwZ)+">") #
works

return(Ww) #Can I

use this?

root = tk.Tk()

root.bind('<Configure>',on_con
figure)

print("15 Ww Inside1 =

<"+str(Ww)+">")

#Ww2 = int(Ww) * 2 # fails
print("17 WwZ Inside2 =

<"+str(WwZ)+">")

root.mainloop()

Ww2 = int(Ww) * 2 #Works

but only after the program
stops

print("21 Ww Outside2 =

<"+str(WwZ)+">") # Can I have
concentric

loops?

SGA

-----Original Message-----
From: Alan Gauld

<learn2program@gmail.com>

Sent: Monday, February 26,

2024 4:04 AM

To: Steve GS

<Gronicus@SGA.Ninja>;
python-list@python.org

Subject: Re: RE: Problem

resizing a window and button
placement

On 26/02/2024 07:56, Steve

GS via Python-list wrote:

Then there is that

discovery

element: Why is my original
idea not working? I still
cannot pass the value back
from the function. What is
different about this

function

that others would have

given

me the value?

There is nothing different,

see the code below.

print() is a function like

any other.

In this case it is called

after you close the window, ie
after mainloop() exits.

But any other function

called inside

mainloop - eg any other

event handler can also access
it.

For example, if you added a

button:

def printW(): print("Button

Ww = ", Ww)

bw = tk.Button(root,

text="Print Width",
command=printW)

bw.pack()

You would be able to print

the value on demand.

import tkinter as tk

Ww = None

def on_configure(*args):
global Ww
Ww =

root.winfo_width()

print("Ww Inside

=<"+str(Ww)+">")

root = tk.Tk()

root.bind('<Configure>',on_con
figure)

root.mainloop()

print("Ww Outside =

<"+str(Ww)+">")

--
Alan G
Author of the Learn to

Program web site
http://www.alan-g.me.uk/

http://www.amazon.com/author/a
lan_gauld

Follow my photo-blog on

Flickr at:

http://www.flickr.com/photos/a
langauldphotos



--
https://mail.python.org/mailma
n/listinfo/python-list

--- SoupGate-Win32 v1.05
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