How to handle a click button event in python module tkinter

问题

I am trying to make a question game in python using tkinter. I am struggling to define a function that can check the answer that the player clicked on and add to a score that is then printed out below the answers.

The outcome of the code whenever I click is that the score is 0 and the question and answers don't change. Also, if I click repeatedly, it prints 0 as a label below each other.

I only included all of my code so that if someone wanted to test the code out for themselves, it wouldn't throw up any errors.

import tkinter
import random
from random import shuffle

score = 0

def check_answer(answer):
    if answer == answers[s][0] or answer == answers[s][1]:
        global score
        score += 1
    lbl = tkinter.Label(window, text=score)
    lbl.pack()


#This sets up a window and names it "The Hunt" but doesn't generate the window
window = tkinter.Tk()
window.title("The Hunt!")

#This sets the background colour
window.configure(background="#1C3F95")

#This generates labels and buttons that are the same or similar colour to the background
welcome = tkinter.Label(window, text="Welcome to the Hunt!", bg="#1C3F95")
begin = tkinter.Button(window, text="Click here to begin", bg="#1C7C95")


#This is my code for the question generation. As I made that for a pygame window, I obviously had to change it slightly

questions = ["What species of bird is also a nickname for New Zealand?", "Which Twins can you play as in Assassin's Creed Syndicate?",
                 "Which year was 'Killing In The Name' Christmas Number one?"]

answers = [["kiwi", "Kiwi", "Falcon", "Sparrow", "Crow"], ["frye", "Frye", "Bank", "Green", "Bundy"], ["2009", "2009",
                                                                                                       "1999", "1993",
                                                                                                       "2004"]]
#I had to do it in two separate lists as it's easier to work with later on
# Also I made the correct answers non-case sensitive to make it easier to test.

r = len(questions)
score = 0
s = random.randrange(0, r, 1)
#This generates a random number within the range of how many questions there are
# and then prints out that question

#This generates a label that displays the randomly generated question
question = tkinter.Label(window, text=questions[s])


list = answers[s]
output = []

for i in range(1, 5):
    output.append(answers[s][i])
shuffle(output)


# this takes the answers that correspond with the randomly generated question and shuffles the answers
# I did this as otherwise, the answer would always be the first answer to appear and the player could exploit this

#This code is what displays the labels and buttons on the window. It lets the computer decide where the best place for
#each component is
welcome.pack()
begin.pack()
question.pack()

for i in output:
    answer = tkinter.Button(window, text=i, command=lambda answer = i: check_answer(i))
    answer.pack()


#I had decided to pack the answers like this as it was easier than typing out each element of the list and also
#more efficent
window.mainloop()
#this is the code that actually generates the window

回答1:

Starting at the top, let's change your check_answer definition to not create a new label every time:

def check_answer(answer):
    if answer == answers[s][0] or answer == answers[s][1]:
        global score
        score += 1
        lbl["text"] = score

Next, we need one small change in your for loop: we want to send answer, not i:

for i in output:
    answer = tkinter.Button(window, text=i, command=lambda answer = i: check_answer(answer))
    answer.pack()

lbl = tkinter.Label(window, text=score)
lbl.pack()

Lastly, we'll add that label that we removed earlier down to the bottom where you had it initially. You can change the location of this by packing it sooner in the code for aesthetics. Your code still doesn't cycle to a new question once one is answered (correctly or otherwise), but at least now you can see when the user answers correctly.

Hope this helps.

回答2:

First of all, you did a small error in the lambda callback:

command=lambda answer=i: check_answer(answer)

It should be.

Then for the many labels, create one label and just change the text:

def check_answer(answer):
    print(answer)
    if answer == answers[s][0] or answer == answers[s][1]:
        global score
        score += 1
    lbl.configure(text=str(score))

(much code i did not copy)

for i in output:
    answer = tkinter.Button(window, text=i, command=lambda answer=i: check_answer(answer))
    answer.pack()

lbl = tkinter.Label(window, text=score)
lbl.pack()

来源：https://stackoverflow.com/questions/48245132/how-to-handle-a-click-button-event-in-python-module-tkinter

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python

button

tkinter

label