\begin{funcdesc}{xrange}{start\, end\, step}

This function is very similar to \code{range()}, but returns an

``xrange object'' instead of a list. This is an opaque sequence type

which yields the same values as the corresponding list, without

actually storing them all simultaneously. The advantage of

\code{xrange()} over \code{range()} is minimal (since \code{xrange()}

still has to create the values when asked for them) except when a very

large range is used on a memory-starved machine (e.g. DOS) or when all

of the range's elements are never used (e.g. when the loop is usually

terminated with \code{break}).

\end{funcdesc}