Documentation of "Terminal IPython options" encourages users to do the wrong thing

[eric-wieser]

This documentation page contains entries like:

This seems to encourage users to set the properties as:

from IPython.core.interactiveshell import InteractiveShell
InteractiveShell.ast_node_interactivity = "all"

whereas I think the intended use is:

get_ipython().ast_node_interactivity = 'all'

Three questions then:

• Is my interpretation of the way to apply these settings correct?
• Can you think of a way to improve the documentation so users don't do this?
• Should the metaclass of InteractiveShell throw an exception if someone tries to do this?