Re: Using SQL to group records with similar elements

On Thu, Jul 21, 2011 at 7:02 PM, Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx> wrote:

I'm not sure I understand this line:

if values<= master:

You're comparing one list to be less than or equal to another?

Ah, good question. Actually, <= is overloaded with a different
meaning for sets. When both operands are sets, it's equivalent to

if values.issubset(master):

Other "mathy" shorthand notation for sets: >= for .issuperset(), |
for .union(), & for .intersection(), - for .difference(), and ^ for
.symmetric_difference() (XOR).

John