mscroggs.co.uk
mscroggs.co.uk

subscribe

Blog

How OEISbot works

 2015-08-29 
A few weeks ago, I made OEISbot, a Reddit bot which posts information whenever an OEIS sequence is mentioned.
This post explains how OEISbot works. The full code can be found on GitHub.

Getting started

OEISbot is made in Python using PRAW (Python Reddit Api Wrapper). PRAW can be installed with:
 bash 
pip install praw
Before making a bot, you will need to make a Reddit account for your bot, create a Reddit app and obtain API keys. This python script can be used to obtain the necessary keys.
Once you have your API keys saved in your praw.ini file, you are ready to make a bot.

Writing the bot

First, the necessary imports are made, and test mode is activated if the script is run with test as an argument. We also define an exception that will be used later to kill the script once it makes a comment.
 python 
import praw
import re
import urllib
import json
from praw.objects import MoreComments

import sys
test = False
if len(sys.argv) > 1 and sys.argv[1] == "test":
    test = True
    print("TEST MODE")

class FoundOne(BaseException):
    pass

To prevent OEISbot from posting multiple links to the same sequence in a thread, lists of sequences linked to in each thread can be loaded and saved using the following functions.
 python 
def save_list(seen, _id):
    print(seen)
    with open("/home/pi/OEISbot/seen/"+_id, "w"as f:
        return json.dump(seen, f)

def open_list(_id):
    try:
        with open("/home/pi/OEISbot/seen/" + _id) as f:
            return json.load(f)
    except:
        return []
The following function will search a post for a mention of an OEIS sequence number.
 python 
def look_for_A(id_, text, url, comment):
    seen = open_list(id_)
    re_s = re.findall("A([0-9]{6})", text)
    re_s += re.findall("oeis\.org/A([0-9]{6})", url)
    if test:
        print(re_s)
    post_me = []
    for seq_n in re_s:
        if seq_n not in seen:
            post_me.append(markup(seq_n))
            seen.append(seq_n)
    if len(post_me) > 0:
        post_me.append(me())
        comment(joiner().join(post_me))
        save_list(seen, id_)
        raise FoundOne
The following function will search a post for a comma-separated list of numbers, then search for it on the OEIS. If there are 14 sequences or less found, it will reply. If it finds a list with no matches on the OEIS, it will message /u/PeteOK, as he likes hearing about possibly new sequences.
 python 
def look_for_ls(id_, text, comment, link, message):
    seen = open_list(id_)
    if test:
        print(text)
    re_s = re.findall("([0-9]+\, *(?:[0-9]+\, *)+[0-9]+)", text)
    if len(re_s) > 0:
        for terms in ["".join(i.split(" ")) for i in re_s]:
            if test:
                print(terms)
            if terms not in seen:
                seen.append(terms)
                first10, total = load_search(terms)
                if test:
                    print(first10)
                if len(first10)>and total <= 14:
                    if total == 1:
                        intro = "Your sequence (" + terms \
                            + ") looks like the following OEIS sequence."
                    else:
                        intro = "Your sequence (" + terms + \
                            + ") may be one of the following OEIS sequences."
                    if total > 4:
                        intro += " Or, it may be one of the " + str(total-4) \
                            + " other sequences listed [here]" \
                            "(http://oeis.org/search?q=" + terms + ")."
                    post_me = [intro]
                    if test:
                        print(first10)
                    for seq_n in first10[:4]:
                        post_me.append(markup(seq_n))
                        seen.append(seq_n)
                    post_me.append(me())
                    comment(joiner().join(post_me))
                    save_list(seen, id_)
                    raise FoundOne
                elif len(first10) == 0:
                    post_me = ["I couldn't find your sequence (" + terms \
                        + ") in the [OEIS](http://oeis.org). "
                        "You should add it!"]
                    message("PeteOK",
                            "Sequence not in OEIS",
                            "Hi Peter, I've just found a new sequence (" \
                            + terms + ") in [this thread](link). " \
                            "Please shout at /u/mscroggs to turn the " \
                            "feature off if its spamming you!")
                    post_me.append(me())
                    comment(joiner().join(post_me))
                    save_list(seen, id_)
                    raise FoundOne

def load_search(terms):
    src = urllib.urlopen("http://oeis.org/search?fmt=data&q="+terms).read()
    ls = re.findall("href=(?:'|\")/A([0-9]{6})(?:'|\")", src)
    try:
        tot = int(re.findall("of ([0-9]+) results found", src)[0])
    except:
        tot = 0
    return ls, tot
The markup function loads the necessary information from OEIS and formats it. Each comment will end with the output of the me function. The ouput of joiner will be used between sequences which are mentioned.
 python 
def markup(seq_n):
    pattern = re.compile("%N (.*?)<", re.DOTALL|re.M)
    desc = urllib.urlopen("http://oeis.org/A" + seq_n + "/internal").read()
    desc = pattern.findall(desc)[0].strip("\n")
    pattern = re.compile("%S (.*?)<", re.DOTALL|re.M)
    seq = urllib.urlopen("http://oeis.org/A" + seq_n + "/internal").read()
    seq = pattern.findall(seq)[0].strip("\n")
    new_com = "[A" + seq_n + "](http://oeis.org/A" + seq_n + "/): "
    new_com += desc + "\n\n"
    new_com += seq + "..."
    return new_com

def me():
    return "I am OEISbot. I was programmed by /u/mscroggs. " \
           "[How I work](http://mscroggs.co.uk/blog/20). " \
           "You can test me and suggest new features at /r/TestingOEISbot/."

def joiner():
    return "\n\n- - - -\n\n"
Next, OEISbot logs into Reddit.
 python 
= praw.Reddit("OEIS link and description poster by /u/mscroggs.")

access_i = r.refresh_access_information(refresh_token=r.refresh_token)
r.set_access_credentials(**access_i)

auth = r.get_me()
The subs which OEISbot will search through are listed. I have used all the math(s) subs which I know about, as these will be the ones mentioning sequences.
 python 
subs = ["TestingOEISbot","math","mathpuzzles","casualmath","theydidthemath",
        "learnmath","mathbooks","cheatatmathhomework","matheducation",
        "puremathematics","mathpics","mathriddles","askmath",
        "recreationalmath","OEIS","mathclubs","maths"]
if test:
    subs = ["TestingOEISbot"]
For each sub OEISbot is monitoring, the hottest 10 posts are searched through for mentions of sequences. If a mention is found, a reply is generated and posted, then the FoundOne exception will be raised to end the code.
 python 
try:
    for sub in subs:
        print(sub)
        subreddit = r.get_subreddit(sub)
        for submission in subreddit.get_hot(limit = 10):
            if test:
                print(submission.title)
            look_for_A(submission.id,
                       submission.title + "|" + submission.selftext,
                       submission.url,
                       submission.add_comment)
            look_for_ls(submission.id,
                        submission.title + "|" + submission.selftext,
                        submission.add_comment,
                        submission.url,
                        r.send_message)

            flat_comments = praw.helpers.flatten_tree(submission.comments)
            for comment in flat_comments:
                if ( not isinstance(comment, MoreComments)
                     and comment.author is not None
                     and comment.author.name != "OEISbot" ):
                    look_for_A(submission.id,
                               re.sub("\[[^\]]*\]\([^\)*]\)","",comment.body),
                               comment.body,
                               comment.reply)
                    look_for_ls(submission.id,
                                re.sub("\[[^\]]*\]\([^\)*]\)","",comment.body),
                                comment.reply,
                                submission.url,
                                r.send_message)

except FoundOne:
    pass

Running the code

I put this script on a Raspberry Pi which runs it every 10 minutes (to prevent OEISbot from getting refusals for posting too often). This is achieved with a cron job.
 bash 
*/10 * * * * python /path/to/bot.py

Making your own bot

The full OEISbot code is available on GitHub. Feel free to use it as a starting point to make your own bot! If your bot is successful, let me know about it in the comments below or on Twitter.
Edit: Updated to describe the latest version of OEISbot.

Similar posts

Logic bot
Raspberry Pi weather station
Logical contradictions
Logic bot, pt. 2

Comments

Comments in green were written by me. Comments in blue were not written by me.
 Add a Comment 


I will only use your email address to reply to your comment (if a reply is needed).

Allowed HTML tags: <br> <a> <small> <b> <i> <s> <sup> <sub> <u> <spoiler> <ul> <ol> <li>
To prove you are not a spam bot, please type "pmuj" backwards in the box below (case sensitive):

Archive

Show me a random blog post
 2020 

Jul 2020

Happy 3e√3π-43 Approximation Day!

May 2020

A surprising fact about quadrilaterals
Interesting tautologies

Mar 2020

Log-scaled axes

Feb 2020

PhD thesis, chapter ∞
PhD thesis, chapter 5
PhD thesis, chapter 4
PhD thesis, chapter 3
Inverting a matrix
PhD thesis, chapter 2

Jan 2020

PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
Christmas (2019) is over
 2019 
▼ show ▼
 2018 
▼ show ▼
 2017 
▼ show ▼
 2016 
▼ show ▼
 2015 
▼ show ▼
 2014 
▼ show ▼
 2013 
▼ show ▼
 2012 
▼ show ▼

Tags

convergence harriss spiral bempp hats game of life weather station sound advent calendar logic raspberry pi chess folding paper radio 4 statistics dates propositional calculus graphs error bars video games programming pythagoras computational complexity gaussian elimination matrix of minors reuleaux polygons speed manchester people maths tmip final fantasy approximation mathsteroids royal institution game show probability ucl javascript signorini conditions stickers fractals boundary element methods big internet math-off electromagnetic field geogebra exponential growth twitter dragon curves estimation sport map projections christmas misleading statistics matt parker nine men's morris cambridge games rugby weak imposition royal baby squares matrix of cofactors puzzles dataset folding tube maps data go wave scattering hannah fry simultaneous equations news chalkdust magazine captain scarlet palindromes asteroids world cup preconditioning football interpolation inline code countdown noughts and crosses sorting php gerry anderson latex talking maths in public machine learning accuracy plastic ratio trigonometry christmas card realhats the aperiodical national lottery hexapawn geometry arithmetic a gamut of games bubble bobble mathslogicbot wool pi approximation day golden spiral finite element method ternary pi chebyshev london underground bodmas logs probability binary oeis triangles numerical analysis flexagons data visualisation frobel matrix multiplication cross stitch reddit coins determinants pac-man polynomials london matrices martin gardner pizza cutting phd sobolev spaces curvature python menace books light mathsjam craft inverse matrices rhombicuboctahedron european cup manchester science festival braiding tennis draughts graph theory quadrilaterals platonic solids golden ratio

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2020