import praw
from pymongo import MongoClient

client = MongoClient('mongodb://localhost:27017/')

db = client['reddit']

reddit = praw.Reddit(client_id="YOUR_CLIENT_ID", client_secret="YOUR_CLIENT_SECRET",
                     user_agent="my user agent", username="YOUR_USERNAME",
                     password="YOUR_PASSWORD")
reddit.read_only = True

fh = reddit.subreddit("SUBREDDIT_NAME")

subreddit = {
    "display_name": fh.display_name,
    "title": fh.title,
    "description": fh.description
}

subreddits = db.subreddits
sub_id = subreddits.insert_one(subreddit).inserted_id

len_sub = 0

for submission in fh.submissions():
    len_sub += 1
    _submission = {
        "title": submission.title,
        "subreddit": sub_id
    }
    submissions = db.submissions
    subm_id = submissions.insert_one(_submission).inserted_id
    submission.comments.replace_more(limit=0)
    for comment in submission.comments.list():
        _comment = {
            "submission": subm_id,
            "body": comment.body
        }
        comments = db.comments
        comments.insert_one(_comment)
    print("There is " + str(len_sub) + " submissions in the subreddit")