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.