update README

Change-Id: If2aabed20685e77bb555022d4a4979f1d9c239a3

README.md

@@ -1,6 +1,6 @@
 # Using the Vision API with Python
 
-Learn how to use various functionality of the Google Cloud Vision API with Python by building 4 separate scripts that highlight a different feature available in the API.
+Learn how to use various functionality of the Google Cloud Vision API with Python by building 4 separate scripts that highlight a different feature available in the API. This is the corresponding code repo for the _Using the Vision API with Python_ codelab (free, self-paced, hands-on tutorial) at <http://g.co/codelabs/vision-python>.
 
 ## Prerequisites
 
@@ -9,7 +9,15 @@ Learn how to use various functionality of the Google Cloud Vision API with Pytho
 - An active GCP billing account
 - Basic Python skills
 
-NOTE: Either Python 2.6+ or 3.6+ is required for this codelab. The Vision API client library code is open source and can be found in [its repo](https://github.com/googleapis/python-vision). The final version that works for Python 2 is v1.0.0.
+**Supported versions:** Python 2.6+ or 3.6+
+
+### Python 2 considerations
+
+
+Python 2 has been [sunset by its community in Jan 2020](http://python.org/doc/sunset-python-2). As such, [support for Python 2 in most Google Cloud products will be waning](https://cloud.google.com/python/docs/python2-sunset) over time (with the except of App Engine, which has [expressed continued long-term support of legacy runtimes](https://cloud.google.com/appengine/docs/standard/long-term-support)). This includes the Vision API, whose final client library version supporting Python 2 is v1.0.0, and whose use is no longer featured in the [Vision API documentation](http://cloud.google.com/vision/docs).
+
+To help accelerate upgrading to 3.x, the scripts in this tutorial only support Python 3 as-is, but commented out code supporting both Python 2 & 3 are available for use if desired. Removing the "# Py2+3" in the code samples gives you a script that works under both Python 2 (under Vision client library v1.0.0) and Python 3 (latest Vision client library). (No "Python 2-only" options are provided.) The Vision API client library source can be found in [its open source repo](https://github.com/googleapis/python-vision).
+
 
 ## Description
 
@@ -25,11 +33,6 @@ Use of the [Vision API is not free](https://cloud.google.com/vision/pricing), ho
 
 ## Resources
 
-### This codelab in other languages
-
-- [.NET/C#](https://codelabs.developers.google.com/codelabs/cloud-vision-api-csharp)
-- [Ruby](https://web.archive.org/web/20201009194731/https://codelabs.developers.google.com/codelabs/cloud-vision-api-ruby) (archived)
-
 ### Cloud Vision API
 
 - [Google Cloud Vision API home page and live demo](https://cloud.google.com/vision)
@@ -46,6 +49,11 @@ Use of the [Vision API is not free](https://cloud.google.com/vision/pricing), ho
 - [Python on the Google Cloud Platform](https://cloud.google.com/python)
 - [GCP Python client libraries](https://googlecloudplatform.github.io/google-cloud-python)
 
+### Other languages
+
+- [.NET/C#](https://codelabs.developers.google.com/codelabs/cloud-vision-api-csharp)
+- [Ruby](https://web.archive.org/web/20201009194731/https://codelabs.developers.google.com/codelabs/cloud-vision-api-ruby) (archived)
+
 ### Support
 
 If you've found an error in the codelab or the sample app, check the [Issues](https://github.com/googlecodelabs/cloud-vision-python/issues) tab to see if there's an open issue or file a new one. Patches are encouraged; please refer to [CONTRIBUTING](CONTRIBUTING.md) for details.