title: python: missing 1 required positional argument: 'self'
body: <p>I try find solution in google but all solution in google not work for me maybe here I get The correct answer.</p>
  <p>I have this code:</p>
  <pre><code>from tkinter import *
  
  
  class gui_main:
      def __init__(self):
  
          self.win_about = Tk() #creat new windows
  
          self.win_about.title(&quot;About software&quot;) # Get title to new windows -&gt; &quot;About software&quot;
  
          self.win_about.geometry(&quot;400x120+600+200&quot;) # Get size to window
  
          self.win_about.resizable(width=False, height=False) # Off option Increase / decrease window
  
          lab = Label(self.win_about, text=&quot;&quot;&quot;
          welcome to app 
          For Enter to app click on button Next.
          &quot;&quot;&quot;, justify='center') # Create new text in the window
          lab.place(x=-18, y=-11) # Position of text in window (x - up/down , y - left/right)
  
          btn_next = Button(self.win_about, text=&quot;Next&quot;, fg=&quot;red&quot;, command=gui_main.screen_menu()) # Create new button
          btn_next.place(x=350, y=90) # Position of button in window (x - up/down , y - left/right)
  
          btn_exit = Button(self.win_about, text=&quot;Exit&quot;, fg=&quot;red&quot;, command=self.win_about.destroy) # Create new button
          btn_exit.place(x=10, y=90) # Position of button in window (x - up/down , y - left/right)
  
          self.win_about.mainloop() # Run the cod in loop
  
      def screen_menu(self):
          self.win_menu = Tk()
          self.win_menu.title(&quot;Menu&quot;)
          self.win_menu.geometry(&quot;500x500+400+400&quot;)
          self.win_about.destroy()
          self.win_menu.mainloop()
  
  if __name__ == &quot;__main__&quot;:
      g = gui_main()
      g.win_about()
  </code></pre>
  <p>And I get this Error:</p>
  <p>Traceback (most recent call last):   File &quot;location file&quot;, line 42, in 
  g = gui_main()   File &quot;location file&quot;, line 26, in <strong>init</strong>
  btn_next = Button(self.win_about, text=&quot;Next&quot;, fg=&quot;red&quot;, command=gui_main.screen_menu()) # Create new button TypeError: screen_menu() missing 1 required positional argument: 'self'</p>
  <p>Ty for help, I will hope find any solution</p>