After successfully deploying a test app using the steps outlined here: http://docs.aws.amazon.com/elasticbeanstalk/latest/dg/create_deploy_Python_flask.html
I tried
Your WSGIPath refers to a file that does not exist.
This error appears because Beanstalk, by default, looks for application.py. Check at Beanstalk web UI, Configuration > Software Configuration, WSGIPath is mapped to application.py
Update the WSGIPath as shown in the previous replies or rename to application.py file.