How to Pass Unique Arguments to Tkinter Buttons Created in a Loop?

Passing Command Arguments in a tkinter Button Creation Loop

In Tkinter, when creating a series of buttons in a for loop, users often face the issue of passing different command arguments to each button. The goal is to identify which button is pressed by extracting the count value (i) during function invocation.

However, when implementing this approach, developers encounter a peculiar problem: regardless of the number of buttons created, the printed value remains the same, corresponding to the final iteration of the loop. This suggests that while the buttons are created independently, the i value in their command arguments appears to be shared.

Resolving the Issue

To overcome this difficulty and assign the correct i value to each button, one needs to modify the lambda function used within the command:

command=lambda: self.open_this(i)

In the original lambda, the i variable is captured at the function definition time, and since it is assigned outside the loop, it has already been replaced with the last loop value by the time the function is called.

The modified lambda resolves this issue by introducing an additional argument i=i, which assigns the current i value to a new variable at the time of the function definition. Hence, each button creation retains the corresponding i value, ensuring proper operation.

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