Setting Spotify credentials using Spotipy - python-2.7

Question

I am trying out spotipy with python 2.7.10 preinstalled on my mac 10.10, specifically [add_a_saved_track.py][1] Here is the code as copied from github:
# Add tracks to 'Your Collection' of saved tracks
import pprint
import sys
import spotipy
import spotipy.util as util
scope = 'user-library-modify'
if len(sys.argv) > 2:
username = sys.argv[1]
tids = sys.argv[2:]
else:
print("Usage: %s username track-id ..." % (sys.argv[0],))
sys.exit()
token = util.prompt_for_user_token(username, scope)
if token:
sp = spotipy.Spotify(auth=token)
sp.trace = False
results = sp.current_user_saved_tracks_add(tracks=tids)
pprint.pprint(results)
else:
print("Can't get token for", username)
I registered the application with developer.spotify.com/my-applications and received client_id and client_secret. I am a bit unclear about selection of redirect_uri so I set that to 'https://play.spotify.com/collection/songs'
Running this from terminal I get an error that says:
You need to set your Spotify API credentials. You can do this by
setting environment variables like so:
export SPOTIPY_CLIENT_ID='your-spotify-client-id'
export SPOTIPY_CLIENT_SECRET='your-spotify-client-secret'
export SPOTIPY_REDIRECT_URI='your-app-redirect-url'
I put that into my code with the id, secret, and url as strings, just following the imports but above the util.prompt_for_user_token method.
That caused a traceback:
File "add-track.py", line 8
export SPOTIPY_CLIENT_ID='4f...6'
^
SyntaxError: invalid syntax
I noticed that Text Wrangler does not recognize 'export' as a special word. And I searched docs.python.org for 'export' and came up with nothing helpful. What is export? How am I using it incorrectly?
I next tried passing the client_id, client_secret, and redirect_uri as arguments in the util.prompt_for_user_token method like so:
util.prompt_for_user_token(username,scope,client_id='4f...6',client_secret='xxx...123',redirect_uri='https://play.spotify.com/collection/songs')
When I tried that, this is what happens in terminal:
User authentication requires interaction with your
web browser. Once you enter your credentials and
give authorization, you will be redirected to
a url. Paste that url you were directed to to
complete the authorization.
Opening https://accounts.spotify.com/authorize?scope=user-library-modify&redirect_uri=https%3A%2F%2Fplay.spotify.com%2Fcollection%2Fsongs&response_type=code&client_id=4f...6 in your browser
Enter the URL you were redirected to:
I entered https://play.spotify.com/collection/songs and then got this traceback:
Traceback (most recent call last):
File "add-track.py", line 21, in <module>
token = util.prompt_for_user_token(username, scope, client_id='4f...6', client_secret='xxx...123', redirect_uri='https://play.spotify.com/collection/songs')
File "/Library/Python/2.7/site-packages/spotipy/util.py", line 86, in prompt_for_user_token
token_info = sp_oauth.get_access_token(code)
File "/Library/Python/2.7/site-packages/spotipy/oauth2.py", line 210, in get_access_token
raise SpotifyOauthError(response.reason)
spotipy.oauth2.SpotifyOauthError: Bad Request
It seems like I am missing something, perhaps another part of Spotipy needs to be imported, or some other python module. It seems I am missing the piece that sets client credentials. How do I do that? I am fairly new at this (if that wasn't obvious). Please help.
UPDATE: I changed redirect_uri to localhost:8888/callback. That causes a Firefox tab to open with an error -- "unable to connect to server." (Since I do not have a server running. I thought about installing node.js as in the Spotify Web API tutorial, but I have not yet). The python script then asks me to copy and paste the URL I was redirected to. Even though FF could not open a page, I got this to work by copying the entire URL including the "code=BG..." that follows localhost:8888/callback? I am not sure this is an ideal setup, but at least it works.
Does it matter if I set up node.js or not?

Answer 1

The process you've followed (including your update) is exactly as the example intends and you are not missing anything! Obviously, it is a fairly simple tutorial, but it sets you up with a token and you should be able to get the information you need.
For the credentials, you can set these directly in your Terminal by running each of the export commands. Read more about EXPORT here: https://www.cyberciti.biz/faq/linux-unix-shell-export-command/