title: How to overwrite label in tkinter, after running another functions
body: <p>I'm making GUI the first time with tkinter(python), and I want to show the results in the same place, where they are at the beginning. </p>
  
  <p>When I run this code the functions are fully working, but I cannot show the results in my label.</p>
  
  <p>The button have to take data from Entries and give it to the function with data from drop-down list.</p>
  
  <p>The results should overwrite the list as1, as2 = [0, 0] and then show the results on the label result_1, result_2</p>
  
  <p>I've tried to add "master" parameter to the function - onclick, but then the GUI was running without clicking the button.</p>
  
  <pre class="lang-py prettyprint-override"><code># coding=utf-8
  from tkinter import *
  
  
  def function_1(h, eta_bet):
      print(h, eta_bet)
      return h, eta_bet
  
  
  def calculated_value_concrete(class_concrete):  # could be 20/25
      eta_bet = class_concrete
      return eta_bet
  
  
  class Menu:
      def __init__(self, master):
          container = Label(master, bg="#003366")
          container.pack()
  
          menu_bg = Label(container, bg="#003366", fg="white", pady=15)
          countings_bg = Label(container)
  
          self.button1 = Button(menu_bg, text="Zbrojenie symetryczne", command=lambda: self.onclick(1, countings_bg),
                                width=20)
  
          menu_bg.pack(side=LEFT, fill=Y)
  
          self.button1.pack()
  
      def onclick(self, args, countings_bg):
          if args == 1:
              countings_bg.pack()
              ZbrojenieSymetryczne(countings_bg)
  
  
  class ZbrojenieSymetryczne:
      def __init__(self, master):
          self.desc_1 = Label(master, text="Wysokość przekroju h [cm]")
          self.desc_7 = Label(master, text="Wybór betonu")
          self.data_1 = Entry(master, width=6)
  
          var = StringVar()
          var.set("Klasa")
  
          self.data_7 = OptionMenu(master, var, "1", "2", command=self.option_menu)
          self.data_7.config(width=10)
  
          self.desc_1.grid(row=1, sticky=E)
          self.desc_7.grid(row=7, sticky=E)
  
          self.data_1.grid(row=1, column=1)
          self.data_7.grid(row=7, column=1, stick="ew")
  
          self.button5 = Button(master, text="Count", command=self.onclick)
          self.button5.grid(row=9, columnspan=2, pady=10)
  
          as1, as2 = [0, 0]
  
          self.result_1 = Label(master, text=f"A_s1 = {as1} [cm^2]")
          self.result_1.grid(row=12, sticky=E)
          self.result_2 = Label(master, text=f"A_s2 = {as2} [cm^2]")
          self.result_2.grid(row=13, sticky=E)
  
      def option_menu(self, selection):
          self.eta_bet = calculated_value_concrete(selection)
          print(self.eta_bet)
  
      def onclick(self):
          h = float(self.data_1.get().replace(',', '.')) * 10 ** -2
  
          as1, as2 = function_1(h, self.eta_bet)
  
          self.result_1 = Label(master, text=f"A_s1 = {as1} [cm^2]")
          self.result_1.grid(row=12, sticky=E)
          self.result_2 = Label(master, text=f"A_s2 = {as2} [cm^2]")
          self.result_2.grid(row=13, sticky=E)
  
  
  root = Tk()
  root.title("Obliczanie zbrojenia")
  
  Menu(root)
  root.mainloop()
  </code></pre>
  
  <p>I want the results in the same label as it is in the beginning (under the button)</p>