How to print something from Entry in another window in Python 3?

Question

Why it does not print the string values I have entered into the textbox in the newwindow?

from tkinter import *

def newwindow():
    newwindow = Tk()
    newwindow.title('Sign Up')
    newwindow.geometry('200x400')

    def sign_done():
        david = a.get()
        javed = b.get()
        lbee = Label(newwindow, text=david).pack()
        baeee = Label(newwindow, text=javed).pack()

    a = StringVar()
    b = StringVar()
    user = Entry(newwindow, textvariable=a).pack()
    pword = Entry(newwindow, textvariable=b).pack()

    done = Button(newwindow, text='done now', command=sign_done).pack()

    newwindow.mainloop()

root = Tk()
root.title('Gulmeena')
root.geometry("500x200")
button = Button(root, text='Go', command=newwindow).pack()

root.mainloop()

Please do not use Classes

Answer 1

Use Tk only to create main window. To create any other window use Toplevel. And use only one mainwindow().

var = Widget(...).pack() assigns None to var because pack()/grid()/place() returns None. You have to do it in two lines.

var = Widget(...) 
var.pack(). 

If you don't need var then you can do

Widget(...).pack()

---

To make code more readable

• I use import tkinter as tk to show I use tk.Button, not ttk.Button nor my own classButton`
• I use name user_var and password_var which means something
• I put all functions at the beginning - even inside newwindow

Code:

import tkinter as tk

def newwindow():

    def sign_done():
        david = user_var.get()
        javed = password_var.get()
        tk.Label(newwindow, text=david).pack()
        tk.Label(newwindow, text=javed).pack()

    newwindow = tk.Toplevel()
    newwindow.title('Sign Up')
    newwindow.geometry('200x400')

    user_var = tk.StringVar()
    password_var = tk.StringVar()

    user = tk.Entry(newwindow, textvariable=user_var)
    user.pack()
    pword = tk.Entry(newwindow, textvariable=password_var)
    pword.pack()

    tk.Button(newwindow, text='done now', command=sign_done).pack()

root = tk.Tk()
root.title('Gulmeena')
root.geometry("500x200")

tk.Button(root, text='Go', command=newwindow).pack()

root.mainloop()

---

You can do the same without StringVars

import tkinter as tk

def newwindow():

    def sign_done():
        david = user.get()
        javed = pword.get()
        tk.Label(newwindow, text=david).pack()
        tk.Label(newwindow, text=javed).pack()

    newwindow = tk.Toplevel()
    newwindow.title('Sign Up')
    newwindow.geometry('200x400')

    user = tk.Entry(newwindow)
    user.pack()
    pword = tk.Entry(newwindow)
    pword.pack()

    tk.Button(newwindow, text='done now', command=sign_done).pack()


root = tk.Tk()
root.title('Gulmeena')
root.geometry("500x200")

tk.Button(root, text='Go', command=newwindow).pack()

root.mainloop()