Michael Foord wrote:
On 9 September 2010 14:32, M.-A. Lemburg <mal@egenix.com> wrote:
[snip...] Why do you need to put everything on one line ?
afh = open(args.actual, encoding="utf-8") efh = open(args.expected, encoding="utf-8")
with afh, efh: ...
In the context of files, the only purpose of the with statement is to close them when leaving the block.
a = open('/etc/passwd') b = open('/etc/group')
If my understanding is correct (which is perhaps unlikely...), using a single line will close a if opening b fails. Whereas doing them separately before the with statement risks leaving the first un-exited if creating the second fails.
Right, but if you stuff everything on a single line, your error handling will have a hard time figuring out which of the two failed to open. I was under the impression that Mark wanted to "protect" the inner block of the with statement, not the context manager creation itself. As usual: hiding away too much stuff in your closet makes things look tidy, but causes a hell of a mess if you ever need to open it again :-)
Michael
with a,b: print a.readline(), b.readline() ... at:x:25:25:Batch jobs daemon:/var/spool/atjobs:/bin/bash at:!:25:
a <closed file '/etc/passwd', mode 'r' at 0x7f0093e62390> b <closed file '/etc/group', mode 'r' at 0x7f0093e62420>
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