Using lambda function to connect buttons in a calculator program and show values after entering

Question

So I am trying to work with the lambda function to connect the buttons of my calculator with a function. Here is some of my code:

button1 = Gtk.Button(label = "1")
lambda event: self.button_clicked(event, "1"), button1
vbox.pack_start(button1 ,True, True, 0)
vbox.pack_end(button1,True,True,0)
self.add(button1)

So I basically want to calculate two numbers when they are clicked but before that I want to to display them in the entry of course. But when I click button1 for example it doesn't get displayed in the text entry. That's basically the problem I need to solve. I think that the button_clicked function should work with all the ifs. That is basically my problem.

def button_clicked(self, value):
    if (value != None):
        if (value != "="):
            # Add something to the text
            self.entry.set_text(self.entry.get_text() + str(value))
        else:
            # Evaluate the text
            self.result = eval(self.entry.get_text())
            self.entry.set_text(self.result)
    else:
        # Clear the text
        self.entry.set_text("")

Am I using the lambda function the right way? And if not how can I change the code?

Answer 1

Since you've now asked similar questions multiple times, this is how it would basically look:

#!/usr/bin/env python3
from gi.repository import Gtk

class Window(Gtk.Window):
    def __init__(self):
        super().__init__()
        self.connect('delete-event', Gtk.main_quit)

        grid = Gtk.Grid()
        for i in range(10):
            button = Gtk.Button(label=str(i))
            button.connect('clicked', self.number_clicked, i)
            grid.attach(button, i%3, i//3, 1, 1)

        self.entry = Gtk.Entry()
        button = Gtk.Button(label='=')
        button.connect('clicked', self.solve_clicked)
        vbox = Gtk.VBox()
        vbox.pack_start(self.entry, False, False, 0)
        vbox.pack_start(grid, True, True, 0)
        vbox.pack_start(button, False, False, 0)

        self.add(vbox)
        self.show_all()

    def number_clicked(self, button, i):
        self.entry.set_text(self.entry.get_text() + str(i))

    def solve_clicked(self, button):
        # here should be the parser for the mathematical expression
        pass


if __name__ == '__main__':
    Window()
    Gtk.main()