trictionary?

[Adam Tomjack]

Randy,

I'd probably use a two element list.

Instead of using an if/else to check if an element is in your dict and 
initialize it, you can use the setdefault() function.  The docs for 
dictionaries explain it pretty well.

      bin = {}
      for whatever:
         for [a, b] in foo:
  	  x = 42 - a
  	  bin_item = bin.setdefault(x, [1, 0])
  	  bin_item[0] += 1
      for x, (y, z) in bin.iteritems():
         print x, y, z

You could also use a class like a C-style struct if you want named items:

class BinItem:
   def __init__(self, s=0, t=0):
     self.s = s
     self.t = t

bin = {}
for a, b in foo:
   x = 42 - a
   bin_item = bin.setdefault(x, BinItem(1, 0))
   bin_item.s += 1

for x, item in bin.iteritems():
   print x, item.s, item.t


Luck in battle,

Adam


Randy Bush wrote:
> i have some code which looks kinda like 
> 
>     bin = {}
>     for whatever:
>        for [a, b] in foo:
> 	  x = 42 - a
> 	  y = 42 - b
> 	  if bin.has_key(x):
> 	     bin[x] += 1
> 	  else:
> 	     bin[x] = 1
>     for i, j in bin.iteritems():
>        print i, j
> 
> now i want to add a second count column, kinda like
> 
>     bin = {}
>     for whatever:
>        for [a, b] in foo:
> 	  x = 42 - a
> 	  if bin.has_key(x):
> 	     bin[x.b] += 1
> 	  else:
> 	     bin[x.b] = 1
> 	     bin[x.not b] = 0
>     for x, y, z in bin.iteritems():
>        print x, y, z
> 
> should the dict value become a two element list, or is
> there a cleaner way to do this?
> 
> randy
>