according to the API documentation, i should be able to use user.update(first_name='name', last_name='name') to update a user's first and last names. however, it is saying that the function update() has no parameters first_name and last_name. i can however update fullname. (but i still need to update first and last)
moved this post to ArcGIS API for Python to increase your chances of getting an answer
Hi thomas - the first_name and last_name parameters were added to the update() function at API release 1.4.0. Can you test that release of the API?
accounts = gis.users.search(query='*')
accounts[0].update(first_name = 'Mike')
accounts[0].update(last_name = 'Tyson')