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Groups > comp.lang.python > #54825
| From | Dave Angel <davea@davea.name> |
|---|---|
| Subject | Re: Handling 3 operands in an expression without raising an exception |
| Date | 2013-09-26 14:22 +0000 |
| References | (6 earlier) <l213jr$p9j$1@dont-email.me> <mailman.350.1380194717.18130.python-list@python.org> <l219tq$o2c$1@dont-email.me> <mailman.354.1380200021.18130.python-list@python.org> <l21d5u$cit$1@dont-email.me> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.355.1380205373.18130.python-list@python.org> (permalink) |
On 26/9/2013 09:34, Νίκος wrote:
> Στις 26/9/2013 3:53 μμ, ο/η Antoon Pardon έγραψε:
>> Op 26-09-13 14:39, Νίκος schreef:
>>> Yes, you are right, in my shell it fails too givign the same error
>>> message as yours, while on the other had in the websste is working.
>>>
>>> Can you explain this please?
>>> why doesnt it fail to both enviroments?
>>
>> Your site and your shell are two different environments. The state
>> of the website environment lets your code succeed while the state
>> of the shell environment, doesn't.
>>
> What modification does it need to also work in the shell environmentthe
> [0] at the end is what complicates things.
Not at all. What complicates/confuses things is trying to do too much
in one line.
The line is trying to solve two separate things. You might now
understand the first of them; the fetching of multiple environment
variables that may or may not exist.
The second thing is the function call to gethostbyname(). If fed
invalid data, this call will throw an exception. So you need to either
put it in a try/catch or somehow pretend that you can know what
constitutes invalid data. One example of invalid data is your default
string. Another might be if one of those environment variables exists,
but isn't reasonable. And a third might be if the domain server
temporarily refuses to recognize a valid hostname.
I'd say you need to put the gethostbyname() in a try/catch, and then
supply some reasonable bogus string for host. Only you will know what
to use there; depending on what you're going to use it for.
ipval = (os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR', "Please throw a gaierror exception")
try:
host = socket.gethostbyaddr(ipval) [0]
except socket.gaierror as exc;
host = "Unknown host"
I don't know the gethostbyaddr(), so i don't know if there are other
exceptions you should also try to catch.
--
DaveA
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Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 10:26 +0300
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 10:48 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 10:51 +0300
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 11:12 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:39 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:46 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:50 +0300
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 12:20 +0300
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 12:04 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:45 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 11:07 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:31 +0300
Re: Handling 3 operands in an expression without raising an exception Maarten <maarten.sneep@knmi.nl> - 2013-09-26 02:52 -0700
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:01 +0200
Re: Handling 3 operands in an expression without raising an exception "James Harris" <james.harris.1@gmail.com> - 2013-09-26 11:53 +0100
Re: Handling 3 operands in an expression without raising an exception alex23 <wuwei23@gmail.com> - 2013-09-27 10:05 +1000
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-26 18:41 +1000
Re: Handling 3 operands in an expression without raising an exception Tim Golden <mail@timgolden.me.uk> - 2013-09-26 09:47 +0100
Re: Handling 3 operands in an expression without raising an exception Nobody <nobody@nowhere.com> - 2013-09-26 09:55 +0100
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:56 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:12 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 13:18 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:41 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 13:51 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 13:07 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 14:25 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 13:47 +0200
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:42 +0000
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 11:24 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 15:39 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 14:53 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 16:34 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 14:22 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 19:58 +0300
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 20:16 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 01:14 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 22:55 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 12:19 +0300
Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-27 09:26 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 13:04 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 10:43 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 14:15 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 12:17 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 15:51 +0300
Re: Handling 3 operands in an expression without raising an exception rusi <rustompmody@gmail.com> - 2013-09-28 10:29 -0700
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-27 15:16 +0000
Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 16:04 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 19:47 +0300
Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-27 16:56 +0000
Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 17:00 +0000
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-27 13:19 -0400
Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-27 18:32 +0100
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-27 18:49 +0000
Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 18:54 +0000
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-27 15:21 -0400
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 01:06 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 22:26 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 12:33 +0300
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-28 20:19 +1000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 16:23 +0300
Re: Handling 3 operands in an expression without raising an exception Andreas Perstinger <andipersti@gmail.com> - 2013-09-28 17:02 +0200
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 19:14 +0300
Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-28 18:53 +0100
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-28 14:21 -0400
Re: Handling 3 operands in an expression without raising an exception Zero Piraeus <z@etiol.net> - 2013-09-28 15:38 -0300
Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-30 11:32 +0000
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-30 21:53 +1000
Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-30 12:56 +0000
Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-28 19:45 +0100
Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-28 19:20 +0000
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-29 09:04 +1000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 10:35 +0300
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 12:35 +0300
Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-29 09:48 +0000
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 14:04 +0300
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:14 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 11:27 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:34 +0300
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-29 21:15 +0000
Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-30 16:07 +0100
Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 15:24 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 09:50 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 13:17 +0300
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 10:57 +0000
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-29 23:58 +1000
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-29 21:01 +0000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:06 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-29 12:48 +0200
Re: Handling 3 operands in an expression without raising an exception Piet van Oostrum <piet@vanoostrum.org> - 2013-09-29 13:24 -0400
Re: Handling 3 operands in an expression without raising an exception MRAB <python@mrabarnett.plus.com> - 2013-09-29 18:44 +0100
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-29 14:45 -0400
Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-30 16:05 +0100
Re: Handling 3 operands in an expression without raising an exception Ben Finney <ben+python@benfinney.id.au> - 2013-09-29 11:35 +1000
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-28 11:59 +1000
Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 12:14 +0300
Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-28 15:53 +0200
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-28 12:15 -0400
Re: Handling 3 operands in an expression without raising an exception Robert Kern <robert.kern@gmail.com> - 2013-09-28 12:18 +0100
Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 17:28 +0200
Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-29 12:07 -0400
Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 23:39 +0200
Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 23:49 +0200
Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-30 02:18 +1000
Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 20:37 +0000
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:38 +0000
Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:38 +0000
Re: Handling 3 operands in an expression without raising an exception Gene Heskett <gheskett@wdtv.com> - 2013-09-29 13:32 -0400
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