Key action: Shift Pressed and Released，pressedreleased,from Tkinter

Key action: Shift Pressed and Released，pressedreleased,from Tkinter

from Tkinter import *class KeyDemo( Frame ):   def __init__( self ):      Frame.__init__( self )      self.pack( expand = YES, fill = BOTH )      self.master.title( 'Demonstrating Keystroke Events' )      self.master.geometry( '350x50' )      self.message1 = StringVar()      self.line1 = Label( self, textvariable = self.message1 )      self.message1.set( 'Type any key or shift' )      self.line1.pack()      self.message2 = StringVar()      self.line2 = Label( self, textvariable = self.message2 )      self.message2.set( '' )      self.line2.pack()      self.master.bind( '<KeyPress-Shift_L>', self.shiftPressed )      self.master.bind( '<KeyRelease-Shift_L>', self.shiftReleased )   def shiftPressed( self, event ):      self.message1.set( 'Shift pressed' )      self.message2.set( 'This key is left shift' )   def shiftReleased( self, event ):      self.message1.set( 'Shift released' )      self.message2.set( 'This key is left shift' )def main():   KeyDemo().mainloop()if __name__ == '__main__':   main()