emote_import.py

from BeautifulSoup import BeautifulSoup
import requests
from slacker import Slacker

slack = Slacker('api key from slack goes here')
target = 'https://nameofslack.slack.com'
targetLogin = 'slackloginemail'
targetPassword = 'password'

def manualLogin(username, password, target):
    data = {'signin': 1, 'redir': '', 'email': username, 'password': password}
    s = requests.session()
    r = s.get(target)
    html = BeautifulSoup(r.text)
    form = html.findAll('form', {'id': 'signin_form'})[0]
    data['crumb'] = form.findAll('input', {'name': 'crumb'})[0]['value']
    r = s.post(target, data=data)
    return s

def cleanEmote(tag):
    if tag[:1] == ':' and tag[-1:] == ':':
        tag = tag[1:-1]
    return tag

def retrieveData():
    targetURL = 'https://forums.somethingawful.com/misc.php?action=showsmilies'
    r = requests.get(targetURL)
    return r.text

def processData(data):
    html = BeautifulSoup(data)
    lis = html.findAll('li', {'class': 'smilie'})
    o = {}
    for li in lis:
        img = li.findAll('img')[0]['src']
        text = cleanEmote(li.findAll('div')[0].text)
        o[text] = img
    return o

def getSlackEmojis():
    d = slack.emoji.list()
    return d.body['emoji']

def checkAgainstSlack(data):
    slackData = getSlackEmojis()
    o = {}
    for emote, url in data.iteritems():
        if emote not in slackData and emote not in [':)', ':(']:
            o[emote] = url
    return o

def retrieveEmote(url):
    r = requests.get(url)
    return r.content

def uploadEmoji(session, target, tag, url):
    u = '{}/customize/emoji'.format(target)
    data = {'add': 1, 'name': tag, 'mode': 'data'}
    r = session.get(u)
    html = BeautifulSoup(r.text)
    data['crumb'] = html.findAll('input', {'name': 'crumb'})[0]['value']
    files = {'img': retrieveEmote(url)}
    r = session.post(u, data=data, files=files, allow_redirects=False)
    r.raise_for_status()
    if b'alert_error' in r.content:
        print 'Error ({}): Likely not valid size-wise.'.format(tag)

d = retrieveData()
n = processData(d)
o = checkAgainstSlack(n)
s = manualLogin(targetLogin, targetPassword, target)

for tag, url in o.iteritems():
    print 'Uploading: {}'.format(tag)
    uploadEmoji(session=s, target=target, tag=tag, url=url)