title: Python Tkinter Call event after every 30 seconds or certain time interval
body: <p>I am writing a program in which I want to send data to socket after every 30 seconds. </p>
  
  <pre><code>import socket
  from Tkinter import *
  import tkMessageBox
  #from threading import *
  import thread
  
  _connect = False
  u_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  
  def conn(IP,PORT):
      try:
          print 'start'
  
          u_sock.connect((IP, PORT))
          print 'success'
          _connect = True
      except socket.error, (value,message):
          if u_sock:
              print 'fail'
              u_sock.close()
              return
  def connFunction():
      IP = IP_entry.get()
      if len(IP) &lt; 7:
          tkMessageBox.showinfo("Error", "Invalid IP Address")
          return
      PORT = int(PORT_entry.get())
      print IP , PORT
      thread.start_new_thread(conn,(IP, PORT, ))
  def SEND():
      print 'Send'
      if(_connect == True):
          print 'sending...'
          Inv = 'DATA'
          u_sock.send(Inv.decode('hex'))
          data = u_sock.recv(4096)
          d = data.encode('hex').upper()
          print 'Received', repr(d)
  
  
  GUI = Tk()
  GUI.title('RFID')
  #GUI.geometry("365x280")
  GUI.wm_iconbitmap('RFID.ico')
  GUI.columnconfigure(8, pad=3)
  
  
  GUI.rowconfigure(8, pad=3)
  
  IP_label = Label(GUI,text = "IP Address: ",borderwidth=5)
  IP_label.grid(column=0, row=1, sticky=W)
  IP_entry = Entry(GUI,width=15,borderwidth=3)
  IP_entry.grid(column=3,row=1,sticky=E)
  PORT_label = Label(GUI,text = "Port: ",borderwidth=5)
  PORT_label.grid(column=8, row=1, sticky=E)
  PORT_entry = Entry(GUI,width=6,borderwidth=3)
  PORT_entry.grid(column=9,row=1,sticky=E)
  
  Conn_button= Button(GUI,text="Connect",command=connFunction,borderwidth=1,height=1,width=12)
  Conn_button.grid(column=16,row=1,padx=10,pady=5,sticky=(W,E))
  #GUI.after(1000,SEND)
  GUI.mainloop()
  </code></pre>
  
  <p>I need to call send function after every 30 seconds or how to create the event which is automatically called after every 30 seconds . I try to do this <code>GUI.after(1000,SEND)</code> but it does not works for me. it calls the SEND function only first time...
  Kindly Help me out with an example. Thanks</p>