itrx/relnotes.md at main · virgesmith/itrx

0.4.0

value_counts now behaves like pandas' value_counts: results are ordered most-common-first (ties by first appearance) instead of sorted by key. Items now only need to be hashable rather than orderable, and counting is O(n) rather than O(n log n).
tee now raises ValueError when n < 1, as its docstring has always stated (previously tee(0) silently discarded the iterator and returned an empty tuple).
repeat(1) now returns a new Itr and leaves the original exhausted, consistent with every other value of n (previously it returned self, so consuming the result also consumed the original in that case only).

next_if(predicate): consume and return the next item only if it satisfies the predicate, otherwise leave it in place and return None (like Rust's Peekable::next_if).
sum() / prod(): terminal aggregations over the remaining items.
dedup(): lazily remove consecutive duplicates, keeping the first of each run (like Rust's dedup); works on infinite iterators.
zip_longest(other, fillvalue=...): like zip, but continues to the end of the longer input, padding with fillvalue.
sorted_by(key, reverse=...): eager stable sort by a key function.

Removed the broken apidoc console script from the distribution: the wheel does not package the scripts module, so the installed command always failed with ModuleNotFoundError. It is a dev-only tool, now run directly from the source tree.

nth is now 0-based, consistent with Rust's Iterator::nth and Python's indexing conventions: nth(0) returns the first item (previously this raised ValueError and nth(1) returned the first item). Update callers by dropping the + 1.
interleave now yields the remaining elements of the longer iterable once the shorter one is exhausted, matching Rust's interleave (previously it stopped at the shorter input, silently dropping the tail).

chunk_by: lazily group consecutive elements sharing a key (the semantics of itertools.groupby / Rust's chunk_by). Unlike groupby it does not sort, so it preserves order and works on infinite iterators.

Clarified that groupby (and value_counts, which builds on it) is eager: it sorts the entire input up front, so it reorders output, requires mutually-orderable keys, and must not be used on infinite sources. Corrected the lazy/eager categorisation in the README.
Corrected the nth docstring, which previously claimed it returned None when out of range (it raises StopIteration).