2.2 features

[Bill Janssen]

> You may be right.  isinstance() and issubclass() are somewhat standard
> in other languages I believe, and hard to misunderstand.  The form
> 
>   if x in list: ...
> 
> looks a lot more confusing.  I may withdraw this idea.

I'd think again.  The problem with isinstance and issubclass is that I
can never remember the order of the arguments.  Something
non-symmetric like "x in type" is much clearer to me, to read and to
write.

Bill