A sample implementation of My MLH using Flask. Requirements: Python 2.7, Flask, and Requests.

app.py

from flask import Flask, jsonify, make_response, redirect, request
import urllib
import requests

app = Flask(__name__)

# Config
callback = 'http://localhost:5000/auth/mlh/callback'
client_id = '[ INSERT CLIENT ID ]'
client_secret = '[ INSERT CLIENT SECRET ]'

# Helpers

def fetch_user(access_token):
  base_url = "https://my.mlh.io/api/v1/user"
  qs = urllib.urlencode({'access_token': access_token})

  # Tokens don't expire, but users can reset them, so best to do some error
  # handling here too.
  return requests.get(base_url + '?' + qs).json()

# Routes

@app.route('/')
def index():
  return "<a href='/auth/mlh'>Login with MLH</a>"

@app.route('/auth/mlh')
def auth_with_provider():
  # Step 1: Request an Authorization Code from My MLH by directing a user to
  # your app's authorize page.

  base_url = "https://my.mlh.io/oauth/authorize"
  qs = urllib.urlencode({
    'client_id': client_id,
    'redirect_uri': callback,
    'response_type': 'code'
  })

  return redirect(base_url + '?' + qs)

@app.route('/auth/mlh/callback', methods=['GET', 'POST'])
def auth_with_provider_callback():
  # Step 2: Assuming the user clicked authorize, we should get an Authorization
  # Code which we can now exchange for an access token.

  code = request.args.get('code')
  base_url = "https://my.mlh.io/oauth/token"
  body = {
    'client_id': client_id,
    'client_secret': client_secret,
    'code': code,
    'grant_type': 'authorization_code',
    'redirect_uri': callback
  }

  if not code:
    # If somehow we got here without a code, tell the user it's an invalid request
    return make_response('Error: No code found', 400)

  resp = requests.post(base_url, json=body)

  if resp.status_code == requests.codes.ok:
    # Step 3: Now we should have an access token which we can use to get the
    # current user's profile information.  In a production app you would
    # create a user and save it to your database at this point.

    user = fetch_user(resp.json()['access_token'])
    return jsonify(user)
  else:
    # Really you should have better error handling
    return make_response('Error: Internal Server Error', 500)

if __name__ == '__main__':
  app.run(debug=True)