53 – Module itertools categorisation

A good way to think about the module itertools is to remember it has five categories of iterables:

1. reshaping iterables: batched, chain, groupby, islice, and pairwise;

2. filtering iterables: compress, dropwhile, filterfalse, and takewhile;

3. combinatorial iterables: combinations, combinations_with_replacement, permutations, and product;

4. infinite iterables: count, cycle, and repeat; and

5. tool-complementing iterables: accumulate, starmap, and zip_longest.

Knowing these five categories should help you remember what tools you have available.

(There’s also tee in itertools, which manipulates iterables but isn’t an iterable itself!)

Further reading:

• Module itertools overview blog article.