title: How to collect a string with Stringvar inside Python tkinter?
body: <p>I'm trying to get an entered information such as grade and a note. For grade I'm using OptionMenu and it prints perfectly, but my note (biljeska) won't print whatsoever</p>
  <p>Code example:</p>
  <pre><code>import tkinter as tk
  import datetime
  dt = datetime.datetime.today()
  class OdabirRazreda():
      def __init__(self):
          self.window2 = tk.Tk()
          g=tk.Button(self.window2,command=self.unos)
          g.pack()
  
          self.ocjena = tk.StringVar()
          self.razred=tk.StringVar()
          self.biljeska=tk.StringVar()
          self.ucenik=tk.StringVar()
          self.window2.mainloop()
  
      def unos(self):
          self.window2.withdraw()
          self.window4 = tk.Tk()
  
          lbl_ocjena = tk.Label(self.window4, text=&quot;Ocjena&quot;)
          self.lbl_biljeska = tk.Label(self.window4, text=&quot;Bilješka:&quot;)
  
  
          lbl_ocjena.grid(row=0, column=0, sticky=tk.W, pady=2)
          self.lbl_biljeska.grid(row=1, column=0, sticky=tk.W, pady=2)
  
  
          ent_ocjena = tk.OptionMenu(self.window4, self.ocjena, &quot;1&quot;, &quot;2&quot;, &quot;3&quot;,&quot;4&quot;,&quot;5&quot;)
          ent_ocjena.grid(row=0, column=1, pady=2, )
  
          ent_biljeska = tk.Entry(master=self.window4,textvariable=self.biljeska)
          ent_biljeska.grid(row=1, column=1, pady=2)
          btn_unesi = tk.Button(self.window4, text='Unesi',command=self.ispis)
          btn_unesi.grid(row=3, column=1,pady=2)
          self.window4.mainloop()
      def ispis(self):
          print(dt.day,dt.month,self.ocjena.get(),self.biljeska.get())
  OdabirRazreda()
  </code></pre>