A "scopeguard" for Python
in [Python]
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From: Alf P. Steinbach on 5 Mar 2010 21:32 * Robert Kern: > On 2010-03-03 09:39 AM, Mike Kent wrote: >> What's the compelling use case for this vs. a simple try/finally? >> >> original_dir = os.getcwd() >> try: >> os.chdir(somewhere) >> # Do other stuff >> finally: >> os.chdir(original_dir) >> # Do other cleanup > > A custom-written context manager looks nicer and can be more readable. > > from contextlib import contextmanager > import os > > @contextmanager > def pushd(path): > original_dir = os.getcwd() > os.chdir(path) > try: > yield > finally: > os.chdir(original_dir) > > > with pushd(somewhere): > ... > > > I don't think a general purpose ScopeGuard context manager has any such > benefits over the try: finally:, though. class pushd( Cleanup ): def __init__( self, path ): original_dir = os.getcwd() os.chdir( path ) self._actions.append( lambda: os.chdir( original_dir ) ) Disclaimer: haven't tested this, but it just occurred to me that for such small init/cleanup wrappers the Cleanup class provides a nice alternative to @contextmanager, as above: fewer lines, and perhaps even more clear code. :-) Cheers, - Alf
From: Gabriel Genellina on 7 Mar 2010 21:00 En Thu, 04 Mar 2010 20:52:04 -0300, Alf P. Steinbach <alfps(a)start.no> escribi�: > Sorry, as with the places noted above, I can't understand what you're > trying to say here. Regarding your posts, neither can I. All the time. Sorry, deciphering your posts would force me to spend much more time than available and I can't afford that - so I'm blocking your messages from now on. -- Gabriel Genellina
From: Alf P. Steinbach on 8 Mar 2010 02:38 * Gabriel Genellina: > En Thu, 04 Mar 2010 20:52:04 -0300, Alf P. Steinbach <alfps(a)start.no> > escribi�: > >> Sorry, as with the places noted above, I can't understand what you're >> trying to say here. > > Regarding your posts, neither can I. All the time. Sorry, deciphering > your posts would force me to spend much more time than available and I > can't afford that - so I'm blocking your messages from now on. You could just ask if there was anything you didn't understand. Even with as little you quote readers can see my approach to that problem: asking. But your response, both the out of context quoting and your comment, seems solely designed to convey a negative impression instead of addressing any technical issue. Cheers, - Alf
From: Steve Holden on 8 Mar 2010 07:28 Alf P. Steinbach wrote: > * Gabriel Genellina: >> En Thu, 04 Mar 2010 20:52:04 -0300, Alf P. Steinbach <alfps(a)start.no> >> escribi�: >> >>> Sorry, as with the places noted above, I can't understand what you're >>> trying to say here. >> >> Regarding your posts, neither can I. All the time. Sorry, deciphering >> your posts would force me to spend much more time than available and I >> can't afford that - so I'm blocking your messages from now on. > > > You could just ask if there was anything you didn't understand. > > Even with as little you quote readers can see my approach to that > problem: asking. > > But your response, both the out of context quoting and your comment, > seems solely designed to convey a negative impression instead of > addressing any technical issue. > This isn't an isolated case, Alf. Physician, heal thyself. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS: http://holdenweb.eventbrite.com/
From: ssteinerX on 8 Mar 2010 09:03
On Mar 8, 2010, at 7:28 AM, Steve Holden wrote: >> >> But your response, both the out of context quoting and your comment, >> seems solely designed to convey a negative impression instead of >> addressing any technical issue. >> > This isn't an isolated case, Alf. Physician, heal thyself. As far as I can tell, this happens on every thread Alf is involved in at one point or another. I'm sure it's "everyone else." S |