mapreducenativepython.py

from itertools import permutations, imap, product
from datetime import datetime, timedelta
from random import random, choice
import string

basetime = datetime(2010,5,5)
airports = map(lambda a: ''.join(a), permutations(string.ascii_uppercase, 3))
flights = []
for i in xrange(1,500000):
  td = timedelta(
    days = random() * 10 % 7, 
    seconds = random() * 100000 % 86399
  )
  flights.append({
    'id': i,
    'departs': basetime + td,
    'arrives': basetime + td + timedelta(seconds=3600),
    'origin': choice(airports),
    'dest': choice(airports),
  })

def validitinerary(tpl):
  (x,y) = tpl
  i = {'seg1': x,
    'seg2': y,
    'cnt': 0}
  if(x['dest'] == y['origin'] and 
    (y['departs'] - x['arrives']).seconds in 
      range(6000,30000)
      ): i['cnt'] = 1
  return i

itineraries = imap(validitinerary, product(flights, flights))
itinerarycnts = {}
for i in itineraries:
  key = (i['seg1']['origin'],i['seg2']['dest'])
  if key in itinerarycnts: 
    itinerarycnts[key] += i['cnt']
  else: 
    itinerarycnts[key] = i['cnt']

print itinerarycnts