gistfile1.py

#!/usr/bin/env python2.6

## MacPorts needless dependency cleaning.  Edit 'keep' first!!!
#
## requires python >= 2.6!
# 
## Vincent Fiano <ynniv@ynniv.com>
 
# FIXME: the packages that you care about go here!
keep = ['libidl', 'graphviz', 'bash-completion']

from subprocess import Popen,PIPE

def shellExec(*args):
  return Popen(args, stdout=PIPE).communicate()[0].split('\n')

installed = [l.split(' ')[2] for l in shellExec("port", "installed")[1:-1]]

def dependentsOf(p):
  lines = shellExec("port", "dependents", p)
  if len(lines) > 0 and "has no dependents" in lines[0]:
    return []
  return [l.split(' ')[0] for l in lines[:-1]]

deptree = dict([[p, dependentsOf(p)] for p in installed])

def prune(p):
  if p in deptree: del(deptree[p])
  for k in deptree.keys():
    try:
      deptree[k].remove(p)
    except ValueError:
      pass # they say this is more "pythonic" than checking first

def remove(p):
  print shellExec("sudo", "port", "uninstall", p)
  prune(p)

def findIndependents():
  return [p for p in deptree.keys() if len(deptree[p]) == 0]

toRemove = []
for p in keep:
  del(deptree[p])

independents = findIndependents()
while (len(independents) > 0):
  toRemove.extend(independents)
  [prune(p) for p in independents]
  
  independents = findIndependents()
  print "independents: %s" % independents

if len(toRemove) > 0:
  print "remove %s?" % ' '.join(toRemove)
  answer = ''
  while not answer in ["yes", "no"]:
    print "type 'yes' or 'no'"
    answer = raw_input()

  if answer == "yes":
    [remove(p) for p in toRemove]
else:
  print "nice and tidy!"