Using bisect in a list of tuples?

In some cases just the simple

bisect(list_of_tuples, (3, None))

will be enough.

Because None will compare less than any integer, this will give you the index of the first tuple starting with at least 3, or len(list_of_tuples) if all of them are smaller than 3. Note that list_of_tuples is sorted.

You can separate out the values into separate lists.

from bisect import bisect

data = [(3, 1), (2, 2), (5, 6)]
fst, snd = zip(*data)
idx = bisect(fst, 2)

Note however, that for bisect to work, your data really should be ordered...

Check the bottom section of the documentation: http://docs.python.org/3/library/bisect.html. If you want to compare to something else than the element itself, you should create a separate list of so-called keys. In your case a list of ints containing only [1] of the tuple. Use that second list to compute the index with bisect. Then use that to both insert the element into the original (list of tuples) and the key ([1] of the tuple) into the new list of keys (list of ints).