Last Updated: February 25, 2016

SQLAlchemy model to dictionary

I'm building an app with AngularJS + Flask on Heroku. I really love how extensible and powerful Flask is. Here is a small pice of code that I use to convert SQLAlchemy model to dictionary and then I serialise it to JSON.

def model_to_dict(inst, cls):
 """
 Jsonify the sql alchemy query result. Skips attr starting with "_"
 """
 convert = { "DATETIME": datetime.datetime.isoformat}
 d = dict()
 for c in cls.__table__.columns:
 if c.name.startswith("_"):
 continue
 v = getattr(inst, c.name)
 current_type = str(c.type)
 if current_type in convert.keys() and v is not None:
 try:
 d[c.name] = convert[current_type](v)
 except:
 d[c.name] = "Error: Failed to covert using ", unicode(convert[c.type])
 elif v is None:
 d[c.name] = unicode()
 else:
 d[c.name] = v
 return d

Instead of using underscore for hiding fields you can write your own serializer e.g. https://github.com/mattupstate/overholt/blob/master/overholt/products/models.py