[Python-Dev] re: Using lists as sets (original) (raw)

Jean-Claude Wippler jcw@equi4.com
Mon, 20 Mar 2000 16:37:19 +0100

gvwilson@nevex.com wrote:

[After discussion with Ping, and weekend thought]

[good stuff]

Allow me to offer yet another perspective on this. I'll keep it short.

Python has sequences (indexable collections) and maps (associative collections). C++'s STL has vectors, sets, multi-sets, maps, and multi-maps.

I find the distinction between these puzzling, and hereby offer another, somewhat relational-database minded, categorization as food for thought:

Let me mark the position between key attributes and residue with ":", so everything before the colon marks the uniquely identifying attributes.

A vector (sequence) is: #:R1,R2,...,RM A set is: K1,K2,...KN: A multi-set is: K1,K2,...KN,#: A map is: K1,K2,...KN:#,R1,R2,...,RM A multi-map is: K1,K2,...KN,#:R1,R2,...,RM

And a somewhat esoteric member of this classification:

A singleton is: :R1,R2,...,RM

I have no idea what this means for Python, but merely wanted to show how a relational, eh, "view" on all this might perhaps simplify the issues.

-jcw