I want to write an application which is portable.
With "portable" I mean that it can be used to access these storages:

amazon s3
google cloud storage
Eucalyptus Storage

The software should be developed using Python.
I am unsure how to start, since I could not find a library which supports all three storages.
You can use boto3 for accessing any services of Amazon.
Portable application: s3 and Google cloud storage