##
from tkinter import Tk, BOTH, Listbox, StringVar, END,Label,Frame,Button,W
class Example(Frame):
    def __init__(self, parent):
        Frame.__init__(self, parent,bg='#ccc')   
        self.parent = parent
        self.var = StringVar()
        self.fnt='Times 18'
        self.data = Data()
        self.initUI()
        
    def initUI(self):
        self.parent.title("Example")          
        self.pack(fill=BOTH, expand=True)
        self.lblQue = Label(self,font=self.fnt)
        self.lblQue.pack(fill=BOTH)
        self.lb = Listbox(self,bg='#ededed',font=self.fnt)
        self.lb.bind("<<ListboxSelect>>", self.onSelect)    
        self.lb.pack(fill=BOTH,expand=True)
        self.lblAns = Label(self, text='', bg='#777',
                      fg='yellow',font='times 22',anchor=W)        
        self.lblAns.pack(fill=BOTH)
        frame = Frame(self,bg='#ccc')
        btnNext= Button(frame,text='Вопрос',command=self.onNext,font=self.fnt)
        btnNext.grid(row=0,column=1,padx=10)
        btnQuit= Button(frame,text='Выход',command=self.parent.destroy,font=self.fnt)
        btnQuit.grid(row=0,column=2,padx=10)
        frame.pack(fill=None)
        
    def onSelect(self,val=None):
        try:
            idx = self.lb.curselection()
            value = self.lb.get(idx)   
            self.lblAns['text']= 'Вы выбрали: '+ value
        except: pass
    def onNext(self):
        que,ans = self.data.get()
        self.lblQue['text'] = que
        self.lblAns['text'] = ''
        self.lb.delete(0,self.lb.size())
        for i in ans: self.lb.insert(END,i)
    
    
class Data(object):
    def __init__(self):
        self.que = ('Чем шплинтуется вал?','Чему равно ускорение свободного падения')
        self.ans =(('Гайка','Винт', 'Болт с левой резьбой', 'Шплинт', 'Шайба','Гровер'),
                   ('7.62','3.62','2.87','4.12','9.8','5.56'))
        self.index = 0
    def get(self):
        ret =  self.que[self.index],self.ans[self.index]
        self.index += 1
        self.index %= len(self.que)
        return ret
    
if __name__ == '__main__':
    root = Tk()
    ex = Example(root)
    root.geometry("640x480+100+100")
    root.mainloop()