I love itertools; it's one of the most beautiful, composable standard libs. "Aha! I have an iteration problem here; I'm sure there is an itertools routine that fits it perfectly" oft passes my lips. Often, my confidence is well-placed, but sometimes, neither itertools nor the recipes included in its docs do quite what I need.
Here I've collected several routines I've reached for but not found. Since these are deceptively tricky to get right, I thought I'd wrap them up into a library. Enjoy! Any additions are welcome; just file a pull request.
chunked(iterable, n)Break an iterable into tuples of a given length.
chunked([1, 2, 3, 4, 5, 6, 7], 3) --> [(1, 2, 3), (4, 5, 6), (7,)]
If the length of
iterableis not evenly divisible byn, the last returned tuple will be shorter.peekable(iterable)Wrapper for an iterator to allow 1-item lookahead
peekable(iterator).peek()returns the value that will next pop out ofnext().collate(*iterables[, key=<key function>, reverse=<bool>])Return an iterable ordered collation of the already-sorted items from each of
iterables, compared by kwargkey.If
reverse=Trueis passed, iterables must return their results in descending order rather than ascending.
More Itertools is under the MIT License. See the LICENSE file.
- 1.0
- Initial release, with
collate,peekable, andchunked. Could really use better docs.
- Initial release, with