Python3 Tkinter display Listbox items in a Label when clicked - python-3.x

Question

I have this listbox as part of a class:
def myListbox(self):
selection = Label(self, text="Please select Country").grid(row=0,column=0)
countries = Listbox(self, width = 20, height = 75)
countries.grid(row=0, column=1)
# I have a function that populates the country names from
# a text file and displays the names in the Listbox.
# I want to be able to select a country from the Listbox
# and have it displayed in a Label
country_display = Label(self, text = "").grid(row = 0, column = 9)
# this is where I'm not sure what code to use.
# my code is
countries.bind("<<ListboxSelect>>",country_display)
At the moment nothing is displaying. What am I missing here?
Thanks

Answer 1

First of all, when you perform the method grid on a widget, it will return None. This means that your variable now holds the value None, instead of the reference to the widget.
Secondly, the method bind, binds a function to an event. This function cannot be called yet. However, in your bind, you try to assign the Label (which is not a function) to the event; this is simply not possible.
In the solution below, a function is assigned to the event, which retrieves the country, and sets the label.
from tkinter import *
countries_list = ["Netherlands",
"America",
"Sweden",
"England"]
class MyClass(Tk):
def myListbox(self):
# better to structure it this way. The method grid simply returns None
# which meant that the variable hold None
# Now, the variable selection holds the widget
selection = Label(self, text="Please select Country")
selection.grid(row=0,column=0)
countries = Listbox(self, width = 20, height = len(countries_list))
countries.grid(row=0, column=1)
for country in countries_list:
countries.insert(END, country)
country_display = Label(self, text = country, width = 15)
country_display.grid(row = 0, column = 9)
def get_country(*x):
# gets which country is selected, and changes
# the label accordingly
country = countries_list[countries.curselection()[0]]
country_display.config(text = country)
countries.bind("<<ListboxSelect>>", get_country)
app = MyClass()
app.myListbox()
edit: for more information on Listbox see http://effbot.org/tkinterbook/listbox.htm
(although I get the feeling you might want to use a Combobox, as described in http://www.tkdocs.com/tutorial/widgets.html?)