App Engine launched in 2008 with the Python 2.5 environment. Over the years we have launched other environments such as PHP, Go, and Java. We also launched a newer Python environment, Python 2.7, which provides many important new features, such as multithreading, concurrent requests, and updated versions of core libraries. Accordingly, we announced the deprecation of Python 2.5 on March 8, 2013.
The time has come to shut down the Python 2.5 environment. Beginning on February 1, 2017 no new deployments to Python 2.5 will be allowed.
Support for Python 2.5 will turned off on a weekly basis beginning on May 16, 2017.
Python 2.5 support will be turned down permanently for all
apps on June 20, 2017. After this shutdown date, the application version will
no longer serve traffic. Users attempting to access the apps will receive an
If you want these application versions to continue operating, you'll need to migrate these to Python 2.7. If you have lost the original source code to the application, you can use appcfg.py to download source code.
If you no longer need the Python 2.5 versions of your application, no action is required. If you no longer need data stored by these application versions, you can delete it yourself.
How to tell whether an app uses Python 2.5
Your app uses Python 2.5 if your
app.yaml file does not contain a line
runtime: or if it contains the line
Alternatively, using the Cloud Console,
select your project, select
App Engine, then select
Versions. The runtime
used by the project is displayed in a column on the right; if it displays
python, then your app is using Python 2.5.
Migrating from Python 2.5 to Python 2.7
Refer to the App Engine migration docs for instructions on migrating App Engine Python 2.5 apps to Python 2.7.
Where to get help
If you run into any trouble migrating your application, and you have a support package, you can get help through your normal support channel. If you don't have a support package, you can get help through the support contact form.
With any deprecation there is a follow-up decommission where the API or service is formally removed. The following table lists the service shutdown (turndown) schedule:
|Decommission Date||Decommission Event|
|February 1, 2017||Starting on this date, no new deployments to Python 2.5 are allowed.|
|May 16, 2017||Beginning of weekly turndowns.|
|June 20, 2017||Python 2.5 support is permanently removed.|