How to print values into a Label in Tkinter
<p>I want to write a small app that counts net amount and tax. I wrote this code and I've tried many times using <code>var.set()</code> based on this <a href="https://stackoverflow.com/questions/2603169/update-tkinter-label-from-variable">post</a> but I have no idea how do it correctly.</p>

<pre><code>from tkinter import *
import tkinter as tk

def count23():
    b = gross.get()
    n = round(b/1.23, 2)
    v = round(b - n, 2)
    # print here works, but prints in shell 

def count8():
    b = gross.get()
    n = round(b/1.08, 2)
    v = round(b - n, 2)

def count5():
    b = gross.get()
    n = round(b/1.05, 2)
    v = round(b - n, 2)

root = tk.Tk()

gross = DoubleVar()
root.geometry('220x200+250+250')

L1 = Label(root, text='Input gross ammount').grid(row=0, column=0, columnspan=5)

E1 = Entry(root, textvariable=gross).grid(row=1, column=1, columnspan=3, sticky='WE', padx=5, pady=5)

L2 = Label(root, text='Choose your tax rate').grid(row=2, column=0, columnspan=5)

B1 = Button(root, text='5 %', command=count5)
B1.grid(row=3, column=0, padx=5, pady=5)

B2 = Button(root, text='8 %', command=count8)
B2.grid(row=3, column=2, padx=5, pady=5)

B3 = Button(root, text='23 %', command=count23)
B3.grid(row=3, column=4, padx=5, pady=5)

L3 = Label(root, text=' ').grid(row=4, column=0, columnspan=5)

L4 = Label(root, text='Net').grid(row=5, column=0, columnspan=2, sticky='WE')

L5 = Label(root, text='TAX').grid(row=5, column=3, columnspan=2, sticky='WE')

L6 = Label(root, relief='raised')
L6.grid(row=6, column=0, columnspan=2, sticky='WE')

L7 = Label(root, relief='raised')
L7.grid(row=6, column=3, columnspan=2, sticky='WE')

root.mainloop()
</code></pre>

<p>I need to print net and tax in L6 and L7 labels. Give me some clues how do it, please.</p>