Don't get any value from python tkinter Entry

Question

I have the following:

class Example(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent
        self.menu()

    def menu(self):
        self.parent.title("Simple menu")
        menubar = Menu(self.parent)
        self.parent.config(menu=menubar)
        configmenu = Menu(menubar, tearoff=0)
        configmenu.add_command(label="Add Player", command=self.addplayer)
        menubar.add_cascade(label="Config", menu=configmenu)
        menubar.add_command(label="Exit", command=self.onexit)

    def onexit(self):
        self.quit()

    def addplayer(self):
        toplevel = Toplevel()
        toplevel.focus_set()
        Label(toplevel, text='first name').grid(row=1, column=0, sticky='W')
        fn = Entry(toplevel, text='first name')
        fn.grid(row=1, column=1, sticky='W')
        indb = insertdb()
        Button(toplevel, text='Save', command=indb.foo(fn.get())).grid(row=4, column=0, pady=1)
        Button(toplevel, text='Abort', command=toplevel.destroy).grid(row=4, column=1, pady=1)


class insertdb():
    def __init__(self):
        # db foo
        return

    def foo(self, fn):
        # toplevel.destroy()
        print(fn)

It's only an example and still not complete. I don't understand,why i do not get any value from fn.get(). After hitting the Save Button, nothing happens.

Answer 1

I'm new myself with tkinter, but perhaps your function is being called at the time the statement is seen by python rather than at run time. I use lambda like this:

x = Button(a, text=c, command=lambda j=c: command(j))  

Maybe you can adjust what I have to your needs.

Answer 2

I'd try defining a separate function for indb.foo(fn.get() , and assigning the function name as the command for the button. You might put it in a try/except format:

def fooget():
    from tkinter import messagebox
    # May need to set nonlocal variable for the Entry here and in addplayer
    try:
        indb.foo(fn.get())
    except:
        messagebox.showerror(message='No luck') # or words to that effect

If you run the script from the command line, it may well give you a helpful error message if it doesn't work.