[Tutor] Code with traceback...Re: Help me.. problem in buildingcalculator application

[Alan Gauld]

Kent has already pointed out the problem of overwriting 
the stringvar, but there is another problem too:

>    def oprClick(self,str11,oprt):


>    self.buttonPlu = Button(self.container3,text='+',
                command = lambda: self.oprClick('+',self.str1.get()))


Check the position of the operator string in the definition versus 
the lambda call....

Alan G.