Preparing Actions for Python 3 Compatibility

CloudBolt is aiming to support Python 3 by version 8.0, and any custom Plug-ins or Actions must also be updated before upgrading. Here is a brief guide to updating your Python code to be compatible with both Python 2 and 3.

One of the easiest tools to automatically check your plugin compatibility is 2to3. Run it on the source files of your Plug-ins, and a diff against the original source file is printed.

Most Plug-ins and Actions won't be using methods or syntax that have significant changes. But there are a few common differences that you should review.

Print statements need to be a method:


Raising exceptions should also use a method to set a specific error message:


Catching exceptions need to use 'as' instead of a comma:



Unicode changes will impact how data is read from external sources like the 'requests' library:

Python 2 Python 3

r = requests.get(‘’)

content = r.content()

r = requests.get(‘’)

content = r.content.decode()


String formatting has changed, and the old % formatting is no longer allowed:

Python 2 Python 3
“%d %s” % (i, s) “{} {}”.format(i, s)
“%d/%d=%f” % (355, 113, 355/113) “{:d}/{:d}={:f}”.format(355, 113, 355/113)


Here are a few excellent resources on the topic that can provide more detailed information:

If you have any trouble updating your code, please review those resource and then contact CloudBolt support at

Have more questions? Submit a request


Please sign in to leave a comment.