youtube_bot.py

import pafy #Docs: http://pythonhosted.org/pafy/
import praw
import urllib.parse
import credentials
import time

#Read and Write Files Doc: https://www.tutorialspoint.com/python3/python_files_io.htm

def load_cache_on_startup(): #loads cached comments on startup in the list
	try:
    	file = open('cache.txt', "r") #r = read only
    	cached_comments = file.read()
    	id_list = cached_comments.split(',')
    	return id_list
	except Exception as e:
		print('Error loading cache on startup')
	

words_to_match = ['youtube.com/watch?v=', 'youtu.be/'] #search criteria for youtube links
blacklist = ['pathofexile']
cache = load_cache_on_startup()

def main():
    reddit = praw.Reddit(user_agent=credentials.user_agent, client_id=credentials.client_id, client_secret=credentials.client_secret,
    					username=credentials.username, password=credentials.password)
    
    subreddit = reddit.subreddit('all')
    comments = subreddit.comments(limit=100)
    for comment in comments:
    	comment_text = comment.body
    	isMatch = any(string in comment_text for string in words_to_match) #finds out if a comment has a youtube link in it
    	if comment.id not in cache and isMatch and comment.subreddit.display_name.lower() not in blacklist:
    		#Get the whole video url
    		try:
    			url = get_youtube_url(str(comment.body))
    			output = construct_table(url) #construct the comment in reddit formatting for tables
    			comment.reply(output)
    			print("Reply successfull")
    			cache.append(comment.id)
    			with open('cache.txt', 'a') as out: #a = appending modus
    				out.write(comment.id + ',') #append comment id to cache
    			update_cache()
    		except Exception as e:
    			print('Error')
    			continue
    	elif comment.id in cache:
    		print("ID already in cache")
    print('Done with 100 comments, wait until restart')

def update_cache():
	file = open('cache.txt', "r") #r = read only
	cached_comments = file.read()
	cache.append(cached_comments.split(',')) #split by , and put in the list

def get_youtube_url(comment_text):
	url = str(comment_text).split("/") #split into it's parts
	stepone = str(url[2]) + "/" + str(url[3]) #left part cutted
	steptwo = str(stepone).split("&ab_channel=") #split right part
	return steptwo[0]

def construct_table(url):
	video = pafy.new(url)
	metadata = {'title':str(video.title), 'author':str(video.author), 'viewcount':str(video.viewcount), 'duration':str(video.duration), 
				'likes':str(video.likes), 'dislikes':str(video.dislikes), 'rating':str(video.rating), 'date':str(video.published),
				'description':str(video.description), 'category':str(video.category), 'keywords':str(video.keywords), 'thumbnail':str(video.thumb), 'id':str(video.videoid)}
	output = (	"Hello! It looks like you posted a YouTube video. I am here to provide you with unncessecary meta information about the video. Enjoy!\n\n" +
				"|Category|Information|\n" + ":--|:--\n" + "Title" + "|" + metadata['title'] + "\n" +
				"Author" + "|" + metadata['author'] + "\n" +
				"Views" + "|" + str(format(int(metadata['viewcount']), ',d')) + "\n" + #format to have commas for every thousand
				"Duration" + "|" + metadata['duration'] + "\n" +
				"Likes" + "|" + metadata['likes'] + "\n" + #doesn't show up
				"Dislikes" + "|" + metadata['dislikes'] + "\n" + #doesn't show up
				"Rating" + "|" + metadata['rating'] + "\n" + #cut decimals
				"Upload Date" + "|" + metadata['date'] + "\n" + #format into a better readable format
				#"Description" + "|" + metadata['description'] + "\n" + #way tooo long sometimes
				"Category" + "|" + metadata['category'] + "\n" +
				"Keywords" + "|" + metadata['keywords'] + "\n" + #remove brackets and '
				"Thumbnail" + "|" + "[Thumbnail](" + metadata['thumbnail'] + ")" + "\n" +
				"Video ID" + "|" + metadata['id'] + "\n" +
				"I'm a bot working hard to help Redditors find easy information about YouTube videos posted here." + "" +
				"If you are unhappy with my services or found a bug, please [write a message](https://www.reddit.com/message/compose?to=maggiforever) to my creator /u/maggiforever."
				)
	return output


#run the program
while True:
	try:
		main()
		time.sleep(10)
	except Exception as e:
		print('Error')