Q on explicitly calling file.close

[Terry Reedy]

Stephen Hansen wrote:

> This is precisely why the with statement exists; to provide a cleaner 
> way to wrap a block in setup and teardown functions. Closing is one. 
> Yeah, you get some extra indentation-- but you sorta have to live with 
> it if you're worried about correct code. I think it's a good compromise 
> between your examples of nasty and nice :)
> 
> def compromise(from_, to_):
>     with file(to_) as to_h:
>         with file(from_) as from_h:
>             for line in from_h:
>                print >> to_h, munge(line)
> 
> It's just too bad that 'with' doesn't support multiple separate "x as y" 
> clauses.

The developers already agreed with you ;-).

"With more than one item, the context managers are processed as if 
multiple with statements were nested:

with A() as a, B() as b:
     suite
is equivalent to

with A() as a:
     with B() as b:
         suite
Changed in version 3.1: Support for multiple context expressions.
"

(I suspect this will also be in 2.7)

Terry Jan Reedy