單擊按鈕后如何繼續循環？

Question

我試圖暫停循環，然后在按下按鈕后繼續循環。 我有一個for循環，該循環從列表中提取問題，然后將其顯示給用戶回答，然后在用戶回答時繼續

用戶單擊下一步后，我該如何繼續。 這是我的代碼在下面

from tkinter import *
class exam:
    global nexq
    def __init__(self,master):
        self.master = master
        self.master.title("tuples inside Lists")
        self.master.geometry("300x300+0+0")
        self.master.resizable(False,False)
        self.panel = Frame(self.master,width=300,height=300,bg="brown")
        self.panel.pack_propagate(0)
        self.panel.pack(fill="both")
        self.ans = IntVar()
        self.board = Text(self.panel, width=40,height=10)
        self.board.grid(rowspan=2,columnspan=3 )
        self.opt1 = Radiobutton(self.panel,text="Nigeria",variable=self.ans,value=1,command=self.startexam)
        self.opt1.grid(row=5,column=0,sticky=W)
        self.opt2 = Radiobutton(self.panel,text="Ghana",variable=self.ans,value=2)
        self.opt2.grid(row=5,column=2,sticky=W)
        self.btnnext = Button(self.panel,text="next",command=self.nextq)
        self.btnnext.grid(row=20,column=0,sticky=W)

    def startexam(self):
        global nexq
        nexq = False
        self.ans.set(0)
        self.qstns = [('what is your name','john','philip','john'),
                      ('where do you stay','Abuja','lagos','lagos'),
                      ('what can you do','sing','program','program')]
        for qustn,optn1,optn2,ans in self.qstns:
            self.board.delete('1.0',END)
            self.board.insert(END,qustn)
            self.opt1.configure(text=optn1)
            self.opt2.configure(text=optn2)
            if not nexq:
                break
            else:
                continue



    def nextq(self):
        global nexq
        nexq = True
        return True

Answer 1

如Reblochon所提到的，您可以使用yield來使用生成器來實現函數的暫停/恢復。 為了了解yield工作原理，強烈建議您在此處閱讀獲得SO最高投票的Python帖子。

以下是使用您的問題作為數據的最小樣本：

import tkinter as tk

root = tk.Tk()

q = tk.Label(root,text="Question")
b = tk.Spinbox(root)
q.pack()
b.pack()

def ask_question():
    qstns = [('what is your name','john','philip','john'),
             ('where do you stay','Abuja','lagos','lagos'),
             ('what can you do','sing','program','program')]
    for i in qstns:
        yield i[0], i[1:]

a = ask_question()

def get_next():
    try:
        start.config(text="Next question")
        question, answer = next(a)
        q.config(text=question)
        b["value"] = answer
    except StopIteration:
        start.config(text="No more questions!",state="disabled",relief="sunken")

start = tk.Button(root,text="Start",command=get_next)
start.pack()

root.mainloop()