from gi.repository import Gtk

import sys

distros = [["Select distribution"], ["Fedora"], ["Mint"], ["Suse"]]

class MyWindow(Gtk.ApplicationWindow):

    def __init__(self, app):

        Gtk.Window.__init__(self, title="Welcome to GNOME", application=app)

        self.set_default_size(200, -1)

        self.set_border_width(10)

        # the data in the model, of type string

        listmodel = Gtk.ListStore(str)

        # append the data in the model

        for i in range(len(distros)):

            listmodel.append(distros[i])

        # a combobox to see the data stored in the model

        combobox = Gtk.ComboBox(model=listmodel)

        # a cellrenderer to render the text

        cell = Gtk.CellRendererText()

        # pack the cell into the beginning of the combobox, allocating

        # no more space than needed

        combobox.pack_start(cell, False)

        # associate a property ("text") of the cellrenderer (cell) to a column (column 0)

        # in the model used by the combobox

        combobox.add_attribute(cell, "text", 0)

        # the first row is the active one by default at the beginning

        combobox.set_active(0)

        # connect the signal emitted when a row is selected to the callback

        # function

        combobox.connect("changed", self.on_changed)

        # add the combobox to the window

        self.add(combobox)

    def on_changed(self, combo):

        # if the row selected is not the first one, write its value on the

        # terminal

        if combo.get_active() != 0:

            print("You chose " + str(distros[combo.get_active()][0]) + ".")

        return True

class MyApplication(Gtk.Application):

    def __init__(self):

        Gtk.Application.__init__(self)

    def do_activate(self):

        win = MyWindow(self)

        win.show_all()

    def do_startup(self):

        Gtk.Application.do_startup(self)

app = MyApplication()

exit_status = app.run(sys.argv)

sys.exit(exit_status)