To determine a unified value with a Python for statement

fori in a: #a>> (True, False, True)
    If not neighbor.get_visited(): #Code that stops if multiple a has a value that is false
        break

Code to be executed once (
...
)

I want to check all the values in a and let the code run once below all true, but if I make an ellse statement, the for statement keeps running while it repeats, and when I take it out, it just runs regardless of the if statement.

Is there a way to check the value in a and proceed with the code below only when they are all the same?

ps. Even if it is not a for statement, it is also good to check the value in the list and execute the code below when it is the same.