python中的板条箱记忆游戏

Question

I'm trying to make a memory game and I'm trying to figure out how to call the action hide_text so that the parameter will be the button I clicked.

from tkinter import *
from random import shuffle

root = Tk()

a = list(range(1, 19))
a = list(a) + list(a)

shuffle(a)

def game():
    count = 0
    for i in a:
        if count == 0:
            posisonx = 0
            posisony = 0
        if count == 6:
            count = 0
            posisonx = 0
            posisony += 1
        button = Button(root,text=f' {i}  ',
                        command=lambda: hide_text())
        button.grid(row=posisony, column=posisonx)
        def hide_text(s):
            s.config(text='')
        posisonx += 1
        count += 1

game()
root.mainloop()

Answer 1

There are two problems to solve here. One is that you can't reference a button until it has been created. The other is correctly capturing the reference once it has.

If you want to pass a command involving a reference to the button, you have to split the creation into two lines:

button = Button(root,text=f' {i}  ')
button.configure(command=...)

You need to bind button to the lambda that you create. There are a couple of ways to do this. If you just do command=lambda: hide_text(button) , all the commands will point to the last button you create in the loop.

One trick is to use the fact that default arguments are bound when the function is created:

button.configure(command=lamda s=button: hide_text(s))

You should take def hide_text outside the loop in this case.

Another way is to capture a closure using a nested function. Put this outside the loop:

def get_hide_text(button):
    def hide_text():
        button.config(text='')
    return hide_text

Then, in the loop, do

button.configure(command=get_hide_text(button))