How do I cleanly do slugs in Python / Flask?

Question

I have a simple web service in Python / Flask against MongoDB: https://github.com/rjurney/Collecting-Data/blob/master/src/python/web/index.py

It repeats @app.route code, like this, over and over:

@app.route("/email/<message_id>")
def email(message_id):
  email = emaildb.find_one({"message_id": message_id})
  print email
  return render_template('partials/email.html', email=email)

# Enable /emails and /emails/ to serve the last 20 emaildb in our inbox unless otherwise specified
default_offsets={'offset1': 0, 'offset2': 0 + config.EMAIL_RANGE}
@app.route('/', defaults=default_offsets)
@app.route('/emails', defaults=default_offsets)
@app.route('/emails/', defaults=default_offsets)
@app.route("/emails/<int:offset1>/<int:offset2>")
def list_emaildb(offset1, offset2):
  offset1 = int(offset1)
  offset2 = int(offset2)
  emails = emaildb.find()[offset1:offset2] # Uses a MongoDB cursor
  nav_offsets = get_offsets(offset1, offset2, config.EMAIL_RANGE)
  data = {'emails': emails, 'nav_offsets': nav_offsets, 'nav_path': '/emails/'}
  return render_template('partials/emails.html', data=data)

default_search={'offset1': 0, 'offset2': 0 + config.EMAIL_RANGE, 'query': False}
@app.route("/emails/search", defaults=default_search)
@app.route("/emails/search/", defaults=default_search)
@app.route("/emails/search/<string:query>", defaults=default_search)
@app.route("/emails/search/<string:query>/<int:offset1>/<int:offset2>")
def search_email(query, offset1, offset2):
  if query == False:
    query = request.args.get('query')
    return redirect('/emails/search/' + query + '/' + str(offset1) + '/' + str(offset2))
  doc_count = offset2 - offset1
  results = elastic.search(query, {'from': offset1, 'size': doc_count}, indexes=["email"])
  emails = process_results(results)
  nav_offsets = get_offsets(offset1, offset2, config.EMAIL_RANGE)
  data = {'emails': emails, 'nav_offsets': nav_offsets, 'nav_path': '/emails/search/', 'query': query}
  return render_template('partials/emails.html', data=data)

This is ugly and offends me. It is repeat junk. How can I make this slug handling cleaner, such that it doesn't repeat for each controller?

Answer 1

How about something like this:

@app.route('/')
@app.route('/emails')
@app.route('/emails/')
@app.route("/emails/<int:offset1>/<int:offset2>")
def list_emaildb(offset1=0, offset2=config.EMAIL_RANGE):
   ...

Btw, not sure if @app.route('/emails') needed, because Flask should redirect /emails to /emails/ if you do have a second one. But maybe you need also /emails (depends really on your needs) so I left it there.