More Itertools

Python’s itertools library is a gem - you can compose elegant solutions for a variety of problems with the functions it provides. In more-itertools we collect additional building blocks, recipes, and routines for working with Python iterables.

Grouping	chunked, ichunked, chunked_even, sliced, constrained_batches, distribute, divide, split_at, split_before, split_after, split_into, split_when, bucket, unzip, batched, grouper, partition
Lookahead and lookback	spy, peekable, seekable
Windowing	windowed, substrings, substrings_indexes, stagger, windowed_complete, pairwise, triplewise, sliding_window, subslices
Augmenting	count_cycle, intersperse, padded, repeat_each, mark_ends, repeat_last, adjacent, groupby_transform, pad_none, ncycles
Combining	collapse, sort_together, interleave, interleave_longest, interleave_evenly, interleave_randomly, zip_offset, zip_broadcast, flatten, roundrobin, prepend, value_chain, partial_product
Concurrency	concurrent_tee, serialize, synchronized
Summarizing	ilen, unique_to_each, sample, consecutive_groups, run_length, map_reduce, join_mappings, exactly_n, is_sorted, all_equal, all_unique, argmin, argmax, minmax, first_true, quantify, iequals
Selecting	islice_extended, first, last, one, only, strictly_n, strip, lstrip, rstrip, filter_except, map_except, filter_map, iter_suppress, nth_or_last, extract, unique_in_window, before_and_after, nth, take, tail, unique_everseen, unique_justseen, unique, duplicates_everseen, duplicates_justseen, classify_unique, longest_common_prefix, takewhile_inclusive
Math	dft, idft, convolve, dotproduct, matmul, polynomial_from_roots, polynomial_derivative, polynomial_eval, reshape, sum_of_squares, transpose
Integer math	factor, is_prime, multinomial, nth_prime, sieve, subfactorial, totient
Statistics	running_min, running_max, running_mean, running_median, running_statistics
Combinatorics	circular_shifts, derangements, gray_product, outer_product, partitions, set_partitions, powerset, powerset_of_sets
	distinct_combinations, distinct_permutations
	combination_index, combination_with_replacement_index, permutation_index, product_index
	nth_combination, nth_combination_with_replacement, nth_permutation, nth_product
	random_combination, random_combination_with_replacement, random_derangement, random_permutation, random_product
	random_ordered_range
Wrapping	always_iterable, always_reversible, countable, consumer, iter_except, sized_iterator with_iter
Others	locate, rlocate, replace, numeric_range, side_effect, iterate, loops, difference, make_decorator, SequenceView, time_limited, map_if, iter_index, consume, tabulate, repeatfunc, doublestarmap

Getting started

To get started, install the library with pip:

pip install more-itertools

The recipes from the itertools docs are included in the top-level package:

>>> from more_itertools import flatten
>>> iterable = [(0, 1), (2, 3)]
>>> list(flatten(iterable))
[0, 1, 2, 3]

Several new recipes are available as well:

>>> from more_itertools import chunked
>>> iterable = [0, 1, 2, 3, 4, 5, 6, 7, 8]
>>> list(chunked(iterable, 3))
[[0, 1, 2], [3, 4, 5], [6, 7, 8]]

>>> from more_itertools import spy
>>> iterable = (x * x for x in range(1, 6))
>>> head, iterable = spy(iterable, n=3)
>>> list(head)
[1, 4, 9]
>>> list(iterable)
[1, 4, 9, 16, 25]

For the full listing of functions, see the API documentation.

Links elsewhere

Blog posts about more-itertools:

Development

more-itertools is maintained by @erikrose and @bbayles, with help from many others.

Some notes on contributing:

In general, please make an issue before opening a pull request. Not all will be accepted, so please save yourself the trouble of creating a PR.
Exception: if you’re fixing a documentation typo, you can skip making an issue.
If you’ve spotted a bug yourself, please make an issue with a description of the problem it causes in your own words.
If you’re using a coding assistant or other automated tool to identify bugs, issues you create need to show examples of production code is affected by the problem. Sanitized code is OK; contrived examples aren’t.
Issues and pull requests from coding assistants or other automated tools that don’t follow these instructions will be closed summarily.

Version History

The version history can be found in documentation.

Metadata

Release files for more-itertools 11.2.1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for more-itertools 11.2.1
File	Size	Uploaded
more_itertools-11.2.1.tar.gz	154.1 kB	Oct 14, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for more-itertools 11.2.1
File	Interpreter	ABI	Platform	Reset
more_itertools-11.2.1-py3-none-any.whl 74.4 kB Oct 14, 2026	Python 3	none	any	Details

Total release size: 228.5 kB

Release files / more_itertools-11.2.1.tar.gz

Download URL	more_itertools-11.2.1.tar.gz
Size	154.1 kB
Tags	Source
SHA-256 checksum How to use checksums	`cbf08fd0af284dc69718b9b76a8e6203df624d70209ea511e4219d350c856f63`
BLAKE2b-256 checksum How to use checksums	`52b8c63995bebbb9ac9c059350e0fb8c82c2420c85aeca7d34e40aecf3df9281`
Upload date	Oct 14, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.11.3`

Release files / more_itertools-11.2.1-py3-none-any.whl

Download URL	more_itertools-11.2.1-py3-none-any.whl
Size	74.4 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`35a7377edd1dd6608dcb2cdf534ded55ea32d49448875ad042cd3f879fb1ded0`
BLAKE2b-256 checksum How to use checksums	`5d573c4b1c6f2e0cc29ba023802458ea3d2a996f87085559e4a5f2192d549532`
Upload date	Oct 14, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.11.3`