On 6/29/2013 12:12 AM, rusi wrote:
On Saturday, June 29, 2013 7:06:37 AM UTC+5:30, Ethan Furman wrote:
On 06/27/2013 03:49 PM, Steven D'Aprano wrote:
[rant]
I think it is lousy design for a framework like argparse to raise a
custom ArgumentError in one part of the code, only to catch it elsewhere
and call sys.exit. At the very least, that ought to be a config option,
and off by default.
Libraries should not call sys.exit, or raise SystemExit. Whether to quit
or not is not the library's decision to make, that decision belongs to
the application layer. Yes, the application could always catch
SystemExit, but it shouldn't have to.
So a library that is explicitly designed to make command-line scripts easier
and friendlier should quit with a traceback?
Really?
So a library that behaves like an app is OK?
No, Steven is right as a general rule (do not raise SystemExit), but
argparse was considered an exception because its purpose is to turn a
module into an app. With the responses I have seen here, I agree that
this is a bit short-sighted, as inflexible behavior. The tracker issue
could use more review and comment.
--
Terry Jan Reedy
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