Before you can run your app in the Python 3 runtime of the App Engine standard environment, you may need to change some of the configuration files that App Engine uses:
app.yaml. This file contains information about your app's code, such as the runtime and the latest version identifier.appengine_config.py. The Python 2 runtime uses this file to install client libraries and provide values for constants and "hook functions". The Python 3 runtime doesn't use this file.
Updating app.yaml
The behavior of some fields in your app.yaml configuration
file has been
modified. Remove any deprecated fields and update other fields as described
in the following table.
| Field | Change type | Description |
|---|---|---|
| entrypoint | Added | entrypoint is a
new optional field
for specifying the command that runs when your app starts. If you do not
specify an entrypoint, App Engine configures and starts the
Gunicorn web server.
|
| threadsafe | Deprecated | All applications are presumed to be threadsafe. If your application isn't
threadsafe, set
max_concurrent_requests
to 1. This may significantly increase your costs.
|
| api_version | Deprecated | No longer used in the Python 3 runtime. |
| builtins | Deprecated | |
| libraries | Deprecated |
Use the requirements.txt file to
declare dependencies
and install client libraries.
|
| handlers | Modified |
|
If you use any of the deprecated fields, App Engine returns an error when you deploy your app.
Removing appengine_config.py
The Python 2 runtime in the App Engine standard environment used the
appengine_config.py
file include vendored third-party libraries. The Python 3 runtime ignores the
appengine_config.py file.
Instead, the Python 3 runtime uses the standard requirements.txt
file to install dependencies,
including dependencies that use native code. For more information, see
Specifying Dependencies
in the Python 3 runtime.
