pymongo with flask

Question

I am trying to return my posts, but instead I get

TypeError: 'Cursor' object is not callable.

How can I correct this? Here is my code:

from flask import Flask  
from flask.ext.pymongo import PyMongo  
app = Flask(__name__)  
mongo = PyMongo(app)  
from pymongo import Connection  
connection = Connection()  
db = connection.test_database  
collection = db.test_collection  

@app.route('/')  
def home_page():  
   post = {"author":"mike","text":"jiii"}  
   posts = db.posts  
   posts.insert(post)  
   return posts.find()

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

Answer 1

When you return something from a Flask handler it must be one of the following types of things:

• A flask.Response object (or a werkzeug.wrappers.Response object). Using Flask's render_template will return a response object.
• A tuple in the form (content, status_code, headers)
• A WSGI callable (A function or callable object that takes two params and returns an iterable).

When you return the PyMongo Cursor object Flask sees that it is not an instance of flask.Response (actually, flask.Flask.response_class) and not a tuple so it assumes that it must be a WSGI object and attempts to call it (hence the error).

The best solution is to either use flask.jsonfiy to return a JSON response or to create a template to render the posts and use render_template to return the appropriate response.