title: Python 3 Tkinter appending label to print user input from entry label
body: <p>Hey guys I have just started learning about GUI's and in particular just started using tkinter. I have spent hours searching forums for what I believe should be an obvious and simple solution and found a few people asking similar questions but i failed to understand the solutions.
  Basically I am just trying to get the user to input a letter with an entry widget and display that on a label when the go button is pressed. If anyone could explain to me how to do this I would be extremely grateful. </p>
  
  <p>Here's the code I have written:  </p>
  
  <pre><code>#!/usr/bin/env python3
  
  from tkinter import*
  from tkinter import ttk
  import random
  
  
  root = Tk()
  root.title('test')
  
  frame = ttk.Frame(root, padding='3 3 12 12 ')
  frame.grid(column=0, row=0, sticky=(N, W, E, S))
  frame.columnconfigure(0, weight=1)
  frame.rowconfigure(0, weight=1)
  
  letter = StringVar()
  
  
  def gobutton(*args):
  
      print_label['text'] += letter
  
  
  print_label = ttk.Label(frame, text="")
  print_label.grid(column=1, row=1, sticky=N)
  
  
  letter_entry = ttk.Entry(frame, width=7, textvariable=letter)
  letter_entry.grid(column=1, row=2, sticky=S)
  
  g_button = ttk.Button(frame, width=7, text='GO', command=gobutton)
  g_button.grid(column=3, row=3, sticky=S)
  
  for child in frame.winfo_children():
      child.grid_configure(padx=5, pady=5)
  
  letter_entry.focus() #WHAT DOES THIS DO?
  root.bind('&lt;Return&gt;', gobutton)
  
  root.mainloop()
  </code></pre>