In ipython terminal :
%pastebin -d "my description" 1-150
returns the url to the gist. However, I want to paste it as a logged in user, into my github account. Additionally, is there a way to create private gist (rather than public) from within ipython.
It is not possible with the current code, it is not even planned on the Roadmap. 
Still this could be done as an extension.
You can also propose patches to current magic, Pull Request are always welcomed.
How to put gist as user (and not anonymous)?