Access legacy bundled services for Python 3

This page describes how to install and use legacy bundled services with the Python 3 runtime for the standard environment. Your app must access the bundled services through the App Engine services SDK for Python 3.

Before you begin

Refer to the list of legacy bundled services APIs you can call in the Python runtime.
Before starting a migration project to Python 3, see the runtime migration overview and migration considerations when using legacy bundled services.

Installing the App Engine services SDK

To install the App Engine services SDK, follow these steps:

Include the SDK with your app by adding the following line to your requirements.txt file:
```
appengine-python-standard>=1.0.0
```
You can find the SDK on GitHub under the appengine-python-standard repository, and on PyPI.

Add the following code in your main Python script. This code creates WSGI middleware that sets the variables required to enable your API calls.

Flask

from flask import Flask
from google.appengine.api import wrap_wsgi_app

app = Flask(__name__)
app.wsgi_app = wrap_wsgi_app(app.wsgi_app)

Django

from DJANGO_PROJECT_NAME.wsgi import application
from google.appengine.api import wrap_wsgi_app

app = wrap_wsgi_app(application)

Pyramid

from pyramid.config import Configurator
from google.appengine.api import wrap_wsgi_app

config = Configurator()
# make configuration settings
app = config.make_wsgi_app()
app = wrap_wsgi_app(app)

WSGI

import google.appengine.api

def app(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    yield b'Hello world!\n'

app = google.appengine.api.wrap_wsgi_app(app)

Update your app.yaml file to specify one or more legacy bundled services. For example:
```
app_engine_bundled_services:
- datastore_v3
- memcache
- user
```
If you use features such as login: admin in the handlers section of app.yaml file, enable the Users API by configuring the user setting in the app_engine_bundled_services list.
To deploy your app, use the gcloud app deploy command.

Migration considerations

You should be aware of the following considerations if you are migrating to the Python 3 runtime and your app uses legacy bundled services.