title: Unable to switch between options
body: <p>I am trying to make a simple application which could show me basic information about my network interface card. The application is working but when I am switching the radio buttons it always shows the same output. How can I fix this?
  I am not sure how it would work on a device which does not have a wifi or ethernet driver installed but that's not the thing which I am asking. The nicInfo returns a tupple and based on the radio buttons it will return MAC and IP address of ehternet or Wi-FI and when it is set to have the initial value zero it will display the info of ethernet and when I try to switch it to wifi it still shows the info of the ethernet.</p>
  
  <pre><code>from Tkinter import *
  from netifaces import ifaddresses, interfaces
  from re import match
  
  class App(Frame):
  
      def __init__(self, root):
          Frame.__init__(self, root)
          self.option_add('*Font', 'Verdana 10 bold')
          self.grid()
          self.create_widgets()
          self.show()
  
      def create_widgets(self):
          self.whichOne = IntVar()
          self.output = StringVar()
          self.whichOne.set(0)
          Radiobutton(self, text = 'Ethernet', padx = 10, pady = 10, variable = self.whichOne, value =0).grid(row=0, column=0, sticky=W)
          Radiobutton(self, text = 'Wi-Fi', padx = 10, pady = 10, variable = self.whichOne, value =1).grid(row=1, column=0, sticky=W)
          Button(self, text='QUIT', fg='red', command=self.quit).grid(row=0, column=1, sticky=W, rowspan=2, columnspan=2)
  
      def show(self):
          self.hexInt = interfaces()
          if True:
              self.nic = self.nicInfo(self.whichOne.get())
              selection = 'The MAC address of your device is %s\n' % (self.nic[0]) + '\nThe IP address of your device is %s\n' % (self.nic[1])
              Label(text=selection).grid(row=2, column=0, columnspan=2)
  
      def nicInfo(self, index):
          self.mac = 'unknown'
          for mainKey in ifaddresses(self.hexInt[index]): # a DICT which contains a LIST, in which is a DICT
              for subKey in ifaddresses(self.hexInt[index])[mainKey][0]: #this zero has to be here
                  if match(r'([0-9a-f]{2}[:-]){5}([0-9a-f]{2})', ifaddresses(self.hexInt[index])[mainKey][0][subKey]):
                      self.mac = ifaddresses(self.hexInt[index])[mainKey][0][subKey].upper()
                  elif match(r'((2[0-5]|1[0-9]|[0-9])?[0-9]\.){3}((2[0-5]|1[0-9]|[0-9])?[0-9])', ifaddresses(self.hexInt[0])[mainKey][0][subKey]) and subKey == 'addr':
                      self.ip = ifaddresses(self.hexInt[index])[mainKey][0][subKey]
          return self.mac, self.ip
  
  if __name__ == '__main__':
      root = Tk()
      root.title('MAC')
      app = App(root)
      app.mainloop()
  </code></pre>