<i>Python lists are actually arrays — contiguous chunks of memory.</i><p>Just wondering here, is this guaranteed to always be the case? Practically it probably is, but does the Python spec (as in: the laguage, not one of it's implementations) say a list must be implemented using contiguous memory of slots with Python objects? That seems so low-level and C-ish. Or does the OP actually mean <i>CPython</i> here for instance?