Declaring and managing dependencies
Dependencies for python applications are declared in a standard
file. For example:
You can use any Linux-compatible Python package in the App Engine flexible environment, including packages that require native (C) extensions.
The Python runtime will automatically install all dependencies
declared in your
requirements.txt during deployment.
Installing dependencies locally
When developing and testing your application locally, it's highly recommended to
to isolate your application's dependencies from your system packages. This also
ensures that your dependencies will be the same version on your local machine
and the deployed application.
If you do not have
virtualenv, you can install it via
[sudo] pip install virtualenv
You can then create a
virtualenv, activate it, and install all of your
virtualenv env source env/bin/activate pip install -r requirements.txt
Now when you run your application you can be confident that only the
dependencies declared in
requirements.txt are available.
Often you will not know your exact dependencies. You can use the virtualenv and
pip to install dependencies and use
to write the name and version of all installed packages to your
virtualenv env source env/bin/activate pip install flask pip install python-memcached pip freeze > requirements.txt
Installing a web framework
You'll need to use a web framework to enable your app to serve web requests. You can use any Python web framework including the following:
To use a particular web framework, just add it to your
Installing a WSGI server
Some web frameworks have built-in WSGI servers; however, few of them are suitable for serving production traffic. Most web applications use a standalone WSGI server such as Gunicorn, uWSGI or Waitress. For more information on installing, configuring, and using a WSGI server see application startup.
Installing the Google Cloud Client library
The Google Cloud Client Library for Python is a client library for accessing Google Cloud Platform services that significantly reduces the boilerplate code you have to write. The library provides high-level API abstractions so they're easier to understand. It embraces idioms of Python, works well with the standard library, and integrates better with your codebase. All this means you spend more time creating code that matters to you.
To install the library locally:
pip install google-cloud
The client library can automatically handle authentication for you locally as well by using the Google Cloud SDK.
gcloud auth login