[Python-3000] PEP 3137 plan of attack

[Greg Ewing]

Jim Jewett wrote:
> I thought that was the reason to return self instead of None.

That would be even more misleading, because you would get
no warning that you had called a mutating method when you
thought you were calling a non-mutating one.

This is the reason that all the existing mutating methods
return None instead of self. It's safer that way.

--
Greg