:meth:`dict.itervalues` methods are no longer supported.
* :func:`map` and :func:`filter` return iterators. If you really need
- a list, a quick fix is e.g. ``list(map(...))``, but a better fix is
+ a list and the input sequences are all of equal length, a quick
+ fix is to wrap :func:`map` in :func:`list`, e.g. ``list(map(...))``,
often to use a list comprehension (especially when the original code
uses :keyword:`lambda`), or rewriting the code so it doesn't need a
list at all. Particularly tricky is :func:`map` invoked for the
regular :keyword:`for` loop (since creating a list would just be
+ If the input sequences are not of equal length, :func:`map` will
+ stop at the termination of the shortest of the sequences. For full
+ compatibility with `map` from Python 2.x, also wrap the sequences in
+ :func:`itertools.zip_longest`, e.g. ``map(func, *sequences)`` becomes
+ ``list(map(func, itertools.zip_longest(*sequences)))``.
* :func:`range` now behaves like :func:`xrange` used to behave, except
it works with values of arbitrary size. The latter no longer