Is there an equivalent of Python's itertools for Java? [closed]

Question

I'm searching for a library (preferably generic) that generates iterable combinations and permutations of data contained in collections. Cartesian product would also be nice.

The best way of describing what I want would be "itertools for Java".

Answer 1

itertools does much more than just combinations and permutations, so (while it would surely be nice to have all of itertools when coding Java;-) you can get away with much less.

For example, for permutations, see here; for combinations, here (both classes are from the same author).

Answer 2

I'm actually making a port of itertools to java: it's called neoitertools

Any feedback appreciated as it still in beta. Missing the "product" function yet, and some intensive tests.

Answer 3

Cartesian product is available here: http://guava-libraries.googlecode.com/svn/trunk/javadoc/com/google/common/collect/Sets.html#cartesianProduct%28java.util.Set...%29

Answer 4

Here you find something that might cover your combinatorial needs bundled in a library:

http://code.google.com/p/combinatoricslib/

Answer 5

I'm just throwing this out there, but shouldn't it be possible to use Python's itertools implementation directly from Java using Jython? Is it a C-based api?

[one Google later]

itertools (Jython API documentation)

Actually, the neoitertools project listed above looks very promising, it appears to be in [very] active development (according to Google code) and looks to be a complete implemetation of the itertools functionality, plus it's available via Maven.

Just my 2 pence.

Answer 6

Few years later, combinatorics seems to fit your needs. Taken from the readme:

Simple permutations
Permutations with repetitions
Simple combinations
Combinations with repetitions
Subsets
Integer Partitions
List Partitions
Integer Compositions