This has been brought up on the Python mailinglists before. Really you want a database where two or more columns are indexed. If anybody wants to work on that please read the previous Python discussions first. Here is one possible implementation:
http://code.activestate.com/recipes/576968/ On Wednesday, September 25, 2013 5:08:12 PM UTC+1, Nathann Cohen wrote: > > Helloooooooo everybody ! > > I was just messing with dictionaries and lists, and I wonder if we > could solve the problem once and for all with an inefficient generic > solution. Here's the thing : > > I often have to define both a function, and its inverse. Something like : > > d = { > 'a' : 1, > 'b' : 2, > 'c' : 1, > 'd' : 3 > } > > Then, I want to find the list of all elements whose image is a 1, or > 2, or 3, and end up defining the following dictionary : > > d_inv = { > 1 : ['a','c'], > 2 : ['b'], > 3 : ['d'] > } > > Aaaaaand it would be sooo nice if there was a way to write d**(-1)[2], > or something of the kind ! Did you ever write a code like this, and > would you be interested by a generic tool for that ? > > Otherwise I'll just keep on computing the inverse of my dictionaries > with a couple of Python lines ;-) > > Have fuuuuuuuun ! > > Nathann > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
