tkinter button commands with lambda in Python

You can fix this problem by creating a closure for i and j with the creation of each lambda:

command = lambda i=i, j=j: update_binary_text(i, j)

You could also create a callback factory with references to the button objects themselves:

def callback_factory(button):    return lambda: button["text"] = "1"

And then in your initialization code:

for j in range(0, number):    new_button = Button(root, text=" ")    new_button.configure(command=callback_factory(new_button))    new_button.pack()    buttonList.append(new_button)

Whenever I need a collection of similar widgets, I find it's simplest to enclose them in an object and pass a bound-method as callback rather than playing tricks with lambda. So, instead of having a list like buttonList[] with widgets, create an object:

class MyButton(object):    def __init__(self, i, j):        self.i = i        self.j = j        self.button = Button(..., command = self.callback)    def callback(self):        . . .

Now, you have a list buttonList[] of these objects, rather than the widgets themselves. To update the text, either provide a method for that, or else access the member directly: buttonList[i].button.configure(. . .) And when the callback is activated, it has the entire object and whatever attributes you might need in self.