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 fields that are no longer supported and update other
fields as described in the following table.
Field | Change type | Description |
---|---|---|
api_version application_readable builtins |
No longer supported | Not applicable in the Python 3 runtime. |
threadsafe | No longer supported | 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.
|
libraries | No longer supported |
Use the requirements.txt file to
declare dependencies
and install client libraries.
|
handlers: login | No longer supported |
The login field is not supported. Use Identity and Access Management (IAM) for user
management.
|
handlers: script | Modified | In the Python 2 runtime, you use the
script
field to route incoming requests to your app's script.
In the Python 3 runtime, you are required to use a web framework with
in-app routing (such as Flask or Django) instead of using the
To migrate your
Static file handling remains unchanged. |
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.