Logged In: YES user_id=820079 Use case for pickable slices. Let A be a numeric array of size M x N. We want to consider sub-arrays in this array like A[:4, :] (the first 4 lines of the array). If we want to store both the array and the information of sub-arrays structures, we need to store slices (we can also store start/end indices of the array ... but this is call a slice so it would be better to have pickable slices). In fact, whenever one wants to write generic algorithm working on "sublist of lists" or "subarrays of arrays" or "sub-items of collection of items", it is nicer to use slice objects explicitly and so store them also explicitly.
Logged In: YES user_id=1039782 Additional use case: I needed picklable slices when logging method calls to a database: __setitem__(self, i, x) could not be logged because the database module attempted to pickle objects such as ('__setitem__', slice(1, 2, 3), []). For other Python users who have run into this problem: the code needed to make slices picklable by copy_reg is available at: http://mail.python.org/pipermail/python-list/2004-November/ 248988.html
