global variable in Tkinter

Question

I am a novice Python/Tkinter user and not clear for me how to pass widget content. I supposed usrtext is a global variable - but it prints an empty string. However, Text has real content. What is the way to pass correctly?

class App(object):

    def __init__(self, root):
        frame = Frame(root)
        frame.grid()
        usrtext = Text(bg = "light yellow", fg = "black",relief=SUNKEN)
        usrtext.grid(row=0, columnspan=16, rowspan=2, sticky=W+E+N+S, padx=5, pady=5)
...
...
def do_it():
    print usrtext       // I'd like to see usrtext _here_
...
...
root = Tk()
root.title("My First Attempt")
usrtext=StringVar()
usrtext=""
...
...
butt1 = Button(root, text='Do it', height=1, width=10, relief=RAISED, command=do_it)
butt1.grid(row=4, column=14)

app = App(root)
root.mainloop()

Fiver · Accepted Answer · 2013-11-16 14:32:51Z

1

Try putting everything inside your application class, then you can reference the widgets via self. You've got the same variable name in multiple places but they don't refer to the same thing.

import Tkinter


class Application(Tkinter.Frame):
    def __init__(self, master):
        Tkinter.Frame.__init__(self, master)
        self.parent = master

        frame = Tkinter.Frame(self)

        self.user_text = Tkinter.Text(frame, relief=Tkinter.SOLID, borderwidth=2)
        self.user_text.grid(
            row=0,
            columnspan=16,
            rowspan=2,
            sticky=Tkinter.W+Tkinter.E+Tkinter.N+Tkinter.S,
            padx=5,
            pady=5)

        self.butt1 = Tkinter.Button(frame, text='Do it!', command=self.do_it)
        self.butt1.grid(row=2, columnspan=16)

        frame.pack(fill=Tkinter.BOTH, expand=1, side=Tkinter.BOTTOM)
        self.pack(fill=Tkinter.BOTH, expand=1)

    def do_it(self):
        user_text_string = self.user_text.get(1.0, Tkinter.END)
        print user_text_string


def main():
    root = Tkinter.Tk()
    app = Application(root)
    app.mainloop()

if __name__ == '__main__':
    main()

answered Nov 16, 2013 at 14:32

Fiver

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1 Comment

furas Over a year ago

I had the same when I answered for PyGame questions. Now I'm tired of this.

furas · Accepted Answer · 2013-11-16 14:39:28Z

1

To get text from Text you use

get(start,end) to get text from Text
insert(position, text) to add text to Text

usrtext.insert(END, "Hello World")

print usrtext.get(1.0, END)

see more: The Tkinter Text Widget

By the way: you use usrtext to two elements

usrtext=StringVar()
usrtext=Text()

so in one moment usrtext is StringVar in other Text - I think it is not what you expect.

edited Nov 16, 2013 at 14:39

answered Nov 16, 2013 at 14:31

furas

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