Merge pull request #3162 from ivanov/output-stream-kwarg adding stream kwarg to current.new_output This was missing, and made unnecessarily clunky to create output cells of stream type using the nbformat API. Before this commit, you had to do something like from IPython.nbformat import current as c output = c.new_output('stream', the_text) output['stream'] = 'stdout' after this commit from IPython.nbformat import current as c output = c.new_output('stream', the_text, stream='stdout') and actually, that stream= argument defaults to 'stdout' if it isn't given. I modified a test that will break if this functionality is ever removed.