I tried to slice a numpy array but this doesn't work since Ruby doesn't understand Python's slice syntax. If I could create a slice object using the Python built-in slice function, I could get around this by passing a slice object to Numpy's getslice method, but afaik there's no way to access this.
Perhaps RubyPython could provide a built-in for this? Access to other Python built-ins would be nice as well, though less necessary. Specifically, access to len and type would be handy.