How to upload data to an development server in appengine (MAC OSx)

First download your data as described here.

Then install Charles Proxy App, start the proxy. Set in Proxy -> Proxy Settings to use not the 8888 port.

Finally start your development server and run this in the console.

$ python /path/to/library/google_appengine_python_1.5.5/ upload_data --url=http://localhost:8888/remote_api --file=test.csv --application=your_app_id --passin