Hi everyone, Just a quick announcement: Last week I made the first release of an open-source package called Combi. It's a package for doing combinatorics in Python. The pitch: Combi lets you explore spaces of permutations and combinations as if they were Python sequences, but without generating all the permutations/combinations in advance. It lets you specify a lot of special conditions on these spaces. It also provides a few more classes that might be useful in combinatorics programming. Information about it: https://pypi.python.org/pypi/combi I hope this package will be useful to people here. Thanks, Ram.