checkbox - Python tkinter checkbutton value always equal to 0

Question

I put the checkbutton on the text widget, but everytime I select a checkbutton, the function checkbutton_value is called, and it returns 0.

Part of the code is :

def callback():

    file_name=askopenfilename()
    column_1rowname,column_name=draw_column(file_name)

    root = Tk()
    root.resizable(width=False,height=False)
    root.wm_title("Column")


    S = Scrollbar(root,orient="vertical")
    text=Text(root,width=15,height=10,yscrollcommand=S.set)
    S.config(command=text.yview)
    S.pack(side="right",fill="y")
    text.pack(side="left",fill="both",expand=True)

    #check the value of the checkbutton
    def checkbutton_value():

        if(var.get()):

            print 1
        else:

            print 0

    var=BooleanVar()
    chk = Checkbutton(root, text=column_1rowname[1], variable=var, command=checkbutton_value)
    text.window_create("end", window=chk)
    text.config(state=DISABLED)


errmsg='Error!'
Button(text='File Open',command=callback).pack(fill=X)


mainloop()

Answer 1

The problem is that you have more than one root window. You should only ever create exactly one instance of Tk, and call mainloop exactly once. If you need additional windows, create instances of Toplevel.

Each root window (and all of its children, and all related StringVars etc.) start a new, independent tcl interpreter. Widgets and variables associated with this window can't be used in another tcl interpreter. In your case, the StringVar is associated with the first root window, but the widget is associated with the second. You can't share data between root windows like that.