Flask AttributeError: 'NoneType' object has no attribute 'split'

Question

from flask import Flask, render_template, request
from sys import argv
import requests
import json

app = Flask(__name__)

def decrementList(words):
    for w in [words] + [words[:-x] for x in range(1,len(words))]:
        url = 'http://ws.spotify.com/search/1/track.json?q='
        request = requests.get(url + "%20".join(w))

        json_dict = json.loads(request.content)
        track_title = ' '.join(w)

        for track in json_dict["tracks"]:
            if track["name"].lower() == track_title.lower() and track['href']:
                return "http://open.spotify.com/track/" + track["href"][14:], words[len(w):]

    return "Sorry, no more track matches found!"

@app.route('/')
def home():
    message = request.args.get('q').split()
    first_arg = ' '.join(message)

    results = []
    while message:
        href, new_list = decrementList(message)
        message = new_list
        results.append(href)

    return render_template('home.html', first_arg=first_arg, results=results)

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

In the code above, when I run this Flask app I get an error AttributeError: 'NoneType' object has no attribute 'split from the home function. When I remove this, I also get an error on the ' '.join(message). Now when both of these are removed I refresh the page and the code runs, but not with the correct outputs. Next, I added the split and joins back in and refreshed the page and the code works perfectly, just as it should with no errors. How can I get this to run properly with out having to remove, refresh and add the join and split?

Answer 1

When there is no "q" in query string, you will get None.None has no methods named split, but string has.

message = request.args.get('q').split()

should be:

message = request.args.get('q', '').split()