How can I display thesubmit buttoninstead of next button in only Question 5th in my code? I have tried to do this, but this is not being. I have made two files respectively main.py and data.json file. Help me to do this.

• • 主文件. py**

from tkinter import *
from tkinter import messagebox as mb
import json
from tkinter import ttk
import tkinter as tk
from tkinter.constants import *

class Quiz:

    def __init__(self):
        
        # set question number to 0
        self.q_no=0
        
        # assigns ques to the display_question function to update later.
        self.display_title()
        self.display_question()
        
        # opt_selected holds an integer value which is used for
        # selected option in a question.
        self.opt_selected=IntVar()
        
        self.opts=self.radio_buttons()
        
        # display options for the current question
        self.display_options()
        
        # displays the button for next and exit.
        self.buttons()
        
        # no of questions
        self.data_size=len(question)
        
        # keep a counter of correct answers
        self.correct=0

    def display_result(self):
        
        # calculates the wrong count
        wrong_count = self.data_size - self.correct
        correct = f"Correct: {self.correct}"
        wrong = f"Wrong: {wrong_count}"
        
        # calcultaes the percentage of correct answers
        score = int(self.correct / self.data_size * 100)
        result = f"Score: {score}%"
        
        # Shows a message box to display the result
        mb.showinfo("Result", f"{result}\n{correct}\n{wrong}")

    def check_ans(self, q_no):
        
        # checks for if the selected option is correct
        if self.opt_selected.get() == answer[q_no]:
            # if the option is correct it return true
            return True
              
    def next_btn(self):
        if self.check_ans(self.q_no):
            self.correct += 1
        
        # Moves to next Question by incrementing the q_no counter
        self.q_no += 1
        
        # checks if the q_no size is equal to the data size
        if self.q_no==self.data_size:
            
            # if it is correct then it displays the score
            self.display_result()
            
            # destroys the GUI
            root.destroy()
        else:
            # shows the next question
            self.display_question()
            self.display_options()

    def buttons(self):
          
        
        # The first button is the Next button to move to the
        # next Question
        next_button = Button(root, text="NEXT",command=self.next_btn,
        width=10,bg="#F2A30F",fg="white",font=("ariel",16,"bold"))
        
        # placing the button on the screen
        next_button.place(x=350,y=380)
        
        # This is the second button which is used to Quit the GUI
        quit_button = Button(root, text="Quit", command=root.destroy,
        width=5,bg="black", fg="white",font=("ariel",16," bold"))
        quit_button.place(x=1445,y=50)

    def display_options(self):
        val=0
        
        # deselecting the options
        self.opt_selected.set(0)
        
        for option in options[self.q_no]:
            self.opts[val]['text']=option
            val+=1

    # This method shows the current Question on the screen
    def display_question(self):
        
        # setting the Question properties
        q_no = Label(root, text=question[self.q_no], width=60,
        font=( 'ariel' ,16, 'bold' ), anchor= 'w' )
        
        #placing the option on the screen
        q_no.place(x=70, y=100)

    # This method is used to Display Title
    def display_title(self):
        
        title = Label(root, text="Your has been started.",
        width=90, bg="#F2A30F",fg="white", font=("ariel", 20, "bold"))
          
        title.place(x=0, y=2)

    def radio_buttons(self):
        
        # initialize the list with an empty list of options
        q_list = []
        
        # position of the first option
        y_pos = 150
        
        # adding the options to the list
        while len(q_list) < 4:
            
            # setting the radio button properties
            radio_btn = Radiobutton(root,text=" ",variable=self.opt_selected,
            value = len(q_list)+1,font = ("ariel",14))
            
            # adding the button to the list
            q_list.append(radio_btn)
            
            # placing the button
            radio_btn.place(x = 100, y = y_pos)
            
            # incrementing the y-axis position by 40
            y_pos += 40
        
        return q_list
    
    
def start():
    global hours, minutes, seconds

    if hours == 4:
        return
    seconds -=1

    if seconds == 00:
        minutes -= 1
        seconds = 60
        
    if minutes == 00 and seconds == 00:
        hours = hours+1

    clock.config(text=f'{hours:02}:{minutes:02}:{seconds:02}')

    root.after(1000, start)

    

root = Tk()

root.geometry('1920x1080')

root.title("EXAM")

clock = tk.Label(root, font=("bold",20), text="00:00:00")
clock.place(x=1300,y=55)
hours,minutes,seconds=0,0,60
start()

with open('data.json') as f:
    data = json.load(f)

question = (data['question'])
options = (data['options'])
answer = (data[ 'answer'])

quiz = Quiz()

root.after(60000,lambda:root.destroy())
root.mainloop()

• • 数据. json**

{
  "question": [
    "Q1. Which of the following is not a keyword in Python language?",
    "Q2. Which character is used in Python to make a single line comment?",
    "Q3. Which one of the following is the correct extension of the Python file?",
    "Q4. In which language is Python written?",
    "Q5. Who developed the Python language?"
  ],
  "answer": [
    1,
    3,
    4,
    3,
    2
  ],
  "options": [

    ["a. val",
      "b. raise",
      "c. try",
      "d. with"
    ],
    ["a. /",
      "b. //",
      "c. #",
      "d. !"
    ],
    ["a. python",
      "b. .p",
      "c. Both a and b",
      "d. .py"
    ],
    ["a. English",
      "b. PHP",
      "c. C",
      "d. All of the above"
    ],
    ["a. Zim Den",
      "b. Guido van Rossum",
      "c. Niene Stom",
      "d. Wick van Rossum"
    ]
  ]
}

我还想显示上一个按钮，但我不知道，我该怎么做？