title: NameError: name 'Frame' is not defined (Python)
body: <p>I have constructed a messaging application, but it seems to have incorrect syntax:</p>
  
  <pre><code> from tkinter import messagebox
  
  
  from AESEncDec import *
  from MD5Hashing import *
  from RSAEncDec import *
  
  color = 'lightblue' #color our background
  
  
  class Application(Frame):
  
      def __init__(self, root=None):
  
          Frame.__init__(self, root)
          self.frame_width = 700
          self.frame_height = 400
  
          # Set configuration our frame
          self.config(width = self.frame_width, height = self.frame_height, bg = color) 
          self.pack()
  
          # Create textBox for input data
          self.textbox_one = Text()
          self.textbox_one.place(x = 30, y = 170, height = 200, width = 300 )
  
          # Create textBox for result
          self.textbox_two = Text()
          self.textbox_two.place(x = 370, y = 170, height = 200, width = 300 )
  
          label_input_text = Label( text = "Input text: ", bg = color)
          label_input_text.place(x = 30, y = 155, height = 10, width = 70 )
  </code></pre>
  
  <p>During execution I get the following error:</p>
  
  <blockquote>
    <p>Traceback (most recent call last):
          File "/home/artur/Documents/MScProject/MSc Project/Task #179276/main_program.py", line 11, in 
            class Application(Frame):
        NameError: name 'Frame' is not defined</p>
  </blockquote>
  
  <p>What might be the problem?</p>