I need to iterate over a circular list, possibly many times, each time starting with the last visited item.
The use case is a connection pool. A client asks for connection, an iterator checks if pointed-to connection is available and returns it, otherwise loops until it finds one that is available.
How can I do this neatly in Python?
If you instead need an immediately created list of the results up to a certain length, rather than iterating on demand: see Repeat list to max number of elements for general techniques, and How to replicate array to specific length array for Numpy-specific techniques.