Year: 2013

by webjunkie on Cron, DB, Paste, Pyramid, Python, SQLAlchemy

Running Standalone SQLAlchemy Scripts in Pyramid

From time to time there comes the need to run automated scripts managed by either Python or Cron. In a recent project I had to run a standalone script that checks records on a database at certain hours. So here’s what I came up with. Most of the script is based on this post by Daniel Mayer.

from paste.deploy import appconfig
from sqlalchemy import engine_from_config
from sqlalchemy.orm.exc import NoResultFound, MultipleResultsFound
#here is where sqlalchemy objects are imported
from PRJ.models import DBSession as db,DBRecords
#import the session manager. This way commits will be handled automatically by the Zope Transaction Manager
import transaction
# Load Application Configuration and Return as Dictionary
conf = appconfig('config:' + 'development.ini',
        relative_to="/var/www/PRJ",
        name="main")
# Bind Engine Based on Config
engine = engine_from_config(conf, 'sqlalchemy.')
db.configure(bind=engine)
#Query the DB
data = db.query(DBRecords).one()
with transaction.manager:
  for record in data:
    #query or update DB
 
by webjunkie on Facebook, Python

Facebook FQL Request Error

Today while attempting to query Events data through FQL, I received the following error:

Impersonated access tokens can only be used with the Graph API.

It was a strange error since I had already created my access token with the right scope. To query the data I’m using the pythonforfacebook SDK which uses https://api.facebook.com/method/fql.query as the url for FQL requests (REST API).
I then tried the graph method (https://graph.facebook.com/fql) which worked perfectly, but the response didn’t include Event pictures and I really need pictures to be present on my events listings. So what worked for me was to make a GET request thought the Graph API instead of a POST.
I use Requests for this so the code is very simple.

data = db.query(Model) #retrieve my access_token from DB
payload = {'q' : query, 'access_token': data.access_token,'format' : 'json'}
res = requests.get('https://graph.facebook.com/fql', params=payload)

With this change everything worked as expected.