def startGen( self, targetGen, targetLen, targetArgs=[], targetKwds={} ):
        """
        Initializes the target generator function with supplied arguments and
        keyword.  Requests Tk to call iterGen after all idle events have been
        handled.
        
        Arguments:
          targetGen:  The target generator function
          targetLen:  The number of iterations in the target generator
          targetArgs: The arguments for the generator function
          targetKwds: The keyword arguments fo the generator function
        Note:
          Having iterGen called by Tk ensures that redraws and other sorts of
          normal Tkinter events can be processed.  Results in the status bar
          updating real-time with execution while allowing the GUI to function
          normally.
        """
        self.targetGen = targetGen( *targetArgs, **targetKwds )
        self.targetLen = targetLen
        self.killBtn.configure( state=NORMAL )
        self.after_idle( self.iterGen )

        Initializes the target generator function with supplied arguments and
        keyword.  Requests Tk to call iterGen after all idle events have been
        handled.
        
        Arguments:
          targetGen:  The target generator function
          targetLen:  The number of iterations in the target generator
          targetArgs: The arguments for the generator function
          targetKwds: The keyword arguments fo the generator function
        Note:
          Having iterGen called by Tk ensures that redraws and other sorts of
          normal Tkinter events can be processed.  Results in the status bar
          updating real-time with execution while allowing the GUI to function
          normally.
        
recipes/Python/576674_StatusMeter_widget_for_Tkinter/recipe-576674.py