HackerSpace Hackathon Problem #2 - Retrieve Reddit’s top cat pictures from today, yesterday, the day before yesterday, and n days ago.

HackerSpace-Hackathon-p2.py

import urllib2
import json
import datetime

'''Constants'''
catSubreddits = ['cat','catpictures','cats','flyingcats','catgifs','lolcats']

''' Prompt for num days back ''' 
nDaysSet=False
while nDaysSet is not True:
	try:
		nDays = int(raw_input("N Days Back > "))
		if(nDays>=0):
			nDaysSet = True
		else:
			print "Must provide positive integer"
	except ValueError, e:
		print "Must provide an integer"

''' Set utc time frames '''
utcNow = datetime.datetime.utcnow()
utcThen = datetime.datetime.utcnow() - datetime.timedelta(days=nDays)

'''Determine reddit top timeframe'''
timeframeWord=None
if(nDays>=0 and nDays<=1):
	timeframeWord='day'
elif(nDays>1 and nDays<=7):
	timeframeWord='week'
elif(nDays>7 and nDays<=31):
	timeframeWord='month'
elif(nDays>31 and nDays<=365):
	timeframeWord='year'
else:
	timeframeWord='all'

'''Build API URL'''

apiBaseUrl = 'http://reddit.com/r/' + '+'.join(catSubreddits) + '/top/.json?t=' + timeframeWord + "&count=25&after="

'''Query for JSON'''

#Setup Reddit crawler
redditOpener = urllib2.build_opener()#reddit is shitty about user agents
redditOpener.addheaders = [('User-agent', 'Stanford Student Hackathon Challenge bot /u/jbackus')]
apiCurrUrl = apiBaseUrl

#crawl posts
topPost = None
while topPost is None:
	topJson = redditOpener.open(apiCurrUrl).read()
	submissions = json.loads(topJson)
	submissions = submissions['data']['children']
	lastPostId = None#Track last id for moving to next set of results

	for submission in submissions:
		lastPostId = submission['data']['id']
		submittedDate = datetime.datetime.fromtimestamp(submission['data']['created_utc'])
		if utcThen <= submittedDate <= utcNow:
			topPost = {
						'title'    : submission['data']['title'],
						'permalink': 'http://reddit.com'+submission['data']['permalink'],
						'url'      : submission['data']['url']
					}
			break
	apiCurrUrl = apiBaseUrl + lastPostId

#Display post

if topPost is not None:
	print "[+] Title: " + topPost['title']
	print "[+] Permalink: " + topPost['permalink']
	print "[+] URL: " + topPost['url']
else:
	print 'No top post'