At the interactive prompt, help(object) is very useful.

It would be nice if it also worked on keywords.

"""
>>> help(object)
Help on class object in module __builtin__:

class object
 |  The most base type
"""

vs 

"""
>>> help(with)
SyntaxError: invalid syntax
"""

At the moment, the workaround is to open the 
documentation, pick a document that doesn't seem quite 
right (language reference?), go to the index, and look 
for the keyword.