seems, google already wrap up for their blobstore of images.
it is really good to have some examples for how i can upload images in flask, since they are different from flask and web2app?
We have struggled for quite some time to get it right, and support drag and drop among other cool things. Just wanted to mention, that there is an alternative flask appengine framework called gae-init and there is also a dedicated version to demonstrate uploading files to it called gae-init-upload. Which of course doesn't fix this issue :)