MongoDB and Pyramid

Basics

If you want to use MongoDB (via PyMongo and perhaps GridFS) via Pyramid, you can use the following pattern to make your Mongo database available as a request attribute.

First add the MongoDB URI to your development.ini file. (Note: user, password and port are not required.)

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 [app:myapp]
 # ... other settings ...
 mongo_uri = mongodb://user:password@host:port/database

Then in your __init__.py, set things up such that the database is attached to each new request:

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from pyramid.config import Configurator

try:
    # for python 2
    from urlparse import urlparse
except ImportError:
    # for python 3
    from urllib.parse import urlparse

from gridfs import GridFS
import pymongo


def main(global_config, **settings):
   """ This function returns a Pyramid WSGI application.
   """
   config = Configurator(settings=settings)
   config.add_static_view('static', 'static', cache_max_age=3600)

   db_url = urlparse(settings['mongo_uri'])
   config.registry.db = pymongo.Connection(
       host=db_url.hostname,
       port=db_url.port,
   )

   def add_db(request):
       db = config.registry.db[db_url.path[1:]]
       if db_url.username and db_url.password:
           db.authenticate(db_url.username, db_url.password)
       return db

   def add_fs(request):
       return GridFS(request.db)

   config.add_request_method(add_db, 'db', reify=True)
   config.add_request_method(add_fs, 'fs', reify=True)

   config.add_route('dashboard', '/')
   # other routes and more config...
   config.scan()
   return config.make_wsgi_app()

Note

Configurator.add_request_method has been available since Pyramid 1.4. You can use Configurator.set_request_property for Pyramid 1.3.

At this point, in view code, you can use request.db as the PyMongo database connection. For example:

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@view_config(route_name='dashboard',
             renderer="myapp:templates/dashboard.pt")
def dashboard(request):
    vendors = request.db['vendors'].find()
    return {'vendors':vendors}

Scaffolds

Niall O'Higgins provides a pyramid_mongodb scaffold for Pyramid that provides an easy way to get started with Pyramid and MongoDB.

Video

Niall O'Higgins provides a presentation he gave at a Mongo conference in San Francisco at https://www.10gen.com/presentation/mongosf-2011/mongodb-with-python-pylons-pyramid