A quick and dirty script that monitors reddit's newest comments and searches for a particular substring in each comment.

bot.py

# New comment monitor for reddit
# 
# Copyright (C) 2014 Kevan Ahlquist
#

import requests
import json
import pprint
from time import sleep

url = r'http://www.reddit.com/comments.json' # Get comments from all subreddits
args = {'limit' : '10', # Retrieve at most 10 comments
		'sort' : 'new'} # Retrieve the newest comments first

# This bot will run until the world ends or an error occurs
# It checks every 5 seconds for new comments and does a basic substring search
while True:
	# Send request to the reddit API
	r = requests.get(url, params=args)

	# Process the results into a JSON object
	rData = r.json()


	# Check if any comments were returned
	if rData['data']['children']:

		# Loop through comments and 
		for comment in rData['data']['children']:
			# Check for a particular substring in the comment body
			if 'truth' in comment['data']['body']:
				# This is where you can do things like:
				#     Print something out to the screen
				#     Send an email
				#     Reply to the comment
				print('"truth" found:')
				print(i['data']['body'])
				print('-----')

		# Make sure we don't process the same comment twice
		# The API will only return comments posted after the comment ID we set here
		if rData['data']['after']:
			args['after'] = rData['data']['after']

	else:
		# No new comments have been posted since we last checked
		pass

	# Wait a few seconds 
	sleep(5)