PEP 343, second look

[Paul Rubin]

Ron Adam <rrr at ronadam.com> writes:
> > A new statement is proposed with the syntax:
> >         with EXPR as VAR:
> >             BLOCK
> >     Here, 'with' and 'as' are new keywords; EXPR is an arbitrary
> >     expression (but not an expression-list)...
> 
> How is EXPR arbitrary?  Doesn't it need to be or return an object that
> the 'with' statement can use?  (a "with" object with an __enter__ and
> __exit__ method?)

That's not a syntactic issue.  "x / y" is a syntactically valid
expression even though y==0 results in in a runtime error.