Comment by jerf

String concatenation is mentioned twice on that page, with the same time given. The first time it has a parenthetical "(small)", the second time doesn't have it. I expect you were looking at the second one when you typed that as I would agree that you can't just label it as a constant time, but they do seem to have meant concatenating "small" strings, where the overhead of Python's object construction would dominate the cost of the construction of the combined string.