function name + tab does not return docstring in IPython

Shift-tab only works when you place the edit cursor inside or after the object. Not when it's at the start of the object. This gotcha is not documented anywhere...!

I filed jupyter issue Shift-Tab completion doesn't work when edit cursor is at the start of the object #1902

Oh, the shortcut is now shift+tab.

To display docstrings in Python one can use ? character as a shorthand.

You can place the ? character before or after (no space allowed) the object you are looking for docs.

To access the source code simply use ?? instead.

Source: Help and Documentation in IPython