[portland] Iterating Through Tuples In A List

[Nick Welch]

On Fri, Feb 15, 2008 at 12:43:36PM -0800, jason kirtland wrote:
> the groupby function in itertools is one way:

> from operator import itemgetter
> from itertools import groupby
> 
> for component, grouped in groupby(rows, key=itemgetter(0)):
>      print component
>      for row in grouped:
>          print "\t%s" % row[3]

Dang, that's pretty sweet.  I remember seeing itemgetter before, but
groupby is a new discovery.

pprint.pprint([
    (component, map(itemgetter(3), grouped))
    for component, grouped
    in groupby(rows, key=itemgetter(0))
])

Functional programming that looks like a perverted SQL.  The world needs
more of this.

-- 
Nick Welch | mack @ incise.org | http://incise.org