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 <[email protected]> Sent: Monday, February 26, 2024 4:04 AM To: Steve GS <[email protected]>; [email protected] 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
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