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From: "Prasad, Ramit" <ramit.prasad@jpmorgan.com>
To: "python-list@python.org" <python-list@python.org>
Subject: RE: resume execution after catching with an excepthook?
Thread-Topic: resume execution after catching with an excepthook?
Thread-Index: AQHNsk4tbm5KClblV0qRT+D1aqbMB5fKWCUAgAApbyA=
Date: Thu, 25 Oct 2012 20:59:14 +0000
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andrea crotti wrote:=0D=0A> 2012/10/25 Steven D'Aprano <steve+comp=2Elang=
=2Epython@pearwood=2Einfo>:=0D=0A> > On Wed, 24 Oct 2012 13:51:30 +0100, an=
drea crotti wrote:=0D=0A> >=0D=0A[snip]=0D=0A> > Without a try=2E=2E=2Eexce=
pt block, execution will cease after an exception is=0D=0A> > caught, even =
when using sys=2Eexcepthook=2E I don't believe that there is any=0D=0A> > w=
ay to jump back to the line of code that just failed (and why would you,=0D=
=0A> > it will just fail again) or the next line (which will likely fail be=
cause=0D=0A> > the previous line failed)=2E=0D=0A> >=0D=0A> > I think the o=
nly way you can do this is to write your own execution loop:=0D=0A> >=0D=0A=
> > while True:=0D=0A> >     try:=0D=0A> >         run(next_command())=0D=
=0A> >     except KeyboardInterrupt:=0D=0A> >         if confirm_quit():=0D=
=0A> >             break=0D=0A> >=0D=0A> >=0D=0A> > Of course you need to m=
ake run() atomic, or use transactions that can be=0D=0A> > reverted or back=
ed out of=2E How plausible this is depends on what you are=0D=0A> > trying =
to do -- Python's Ctrl-C is not really designed to be ignored=2E=0D=0A> >=
=0D=0A> > Perhaps a better approach would be to treat Ctrl-C as an uncondit=
ional=0D=0A> > exit, and periodically poll the keyboard for another key pre=
ss to use as=0D=0A> > a conditional exit=2E Here's a snippet of platform-sp=
ecific code to get a=0D=0A> > key press:=0D=0A> >=0D=0A> > http://code=2Eac=
tivestate=2Ecom/recipes/577977=0D=0A> >=0D=0A> > Note however that it block=
s if there is no key press waiting=2E=0D=0A> >=0D=0A> > I suspect that you =
may need a proper event loop, as provided by GUI=0D=0A> > frameworks, or cu=
rses=2E=0D=0A> >=0D=0A> =0D=0A> Ok thanks, but here the point is not to res=
ume something that is going=0D=0A> to fail again, just to avoid accidental =
kill of processes that take a=0D=0A> long time=2E  Probably needed only by =
me in debugging mode, but anyway I=0D=0A> can do the simple try/except then=
, thanks=2E=2E=0D=0A=0D=0AOn the other hand, if you store state externally =
(pickle?) maybe =0D=0Ayou can just restart at the last "check point"=2E Tha=
t way even if=0D=0Athe program dies you can recover on the next run=2E=0D=
=0A=0D=0ARamit Prasad=0D=0A=0D=0A=0D=0AThis email is confidential and subje=
ct to important disclaimers and=0D=0Aconditions including on offers for the=
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aimers,=0D=0Aavailable at http://www=2Ejpmorgan=2Ecom/pages/disclosures/ema=
il=2E