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Groups > comp.lang.python > #48238
| Date | 2013-06-15 10:14 +1000 |
|---|---|
| From | Cameron Simpson <cs@zip.com.au> |
| Subject | Re: Eval of expr with 'or' and 'and' within |
| References | <kpep0v$spl$8@news.ntua.gr> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.3351.1371257115.3114.python-list@python.org> (permalink) |
On 14Jun2013 12:50, Nikos as SuperHost Support <support@superhost.gr> wrote:
| I started another thread because the last one was !@#$'ed up by
| irrelevant replies and was difficult to jeep track.
|
| >>> name="abcd"
| >>> month="efgh"
| >>> year="ijkl"
|
| >>> print(name or month or year)
| abcd
|
| Can understand that, it takes the first string out of the 3 strings
| that has a truthy value.
|
| >>> print("k" in (name and month and year))
| True
|
| No clue. since the expression in parenthesis returns 'abcd' how can
| 'k' contained within 'abcd' ?
Did you print the result of "name and month and year"? It is the
_last_ value (if true at all). You used "or" in the first example
and "and" in the second.
| >>> print(name and month and year)
| ijkl
|
| Seems here is returning the last string out of 3 strings, but have
| no clue why Python doing this.
To evaluate an "and" it must test all of them to be true, and it
keeps the last value tested. (Or False, of course, if they are not
all true, in which case Python stops testing at the first False).
But for what you are doing, "and" and "or" are not good operations.
Something like:
"k" in (name+month+year)
or
"k" in name or "k" in month or "k" in year
is a more direct and accurate way to write what I imagine you're trying to do.
Cheers,
--
Cameron Simpson <cs@zip.com.au>
No one is completely worthless... they can always serve as a bad example.
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Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-14 12:50 +0300
Re: Eval of expr with 'or' and 'and' within Fábio Santos <fabiosantosart@gmail.com> - 2013-06-14 11:03 +0100
Re: Eval of expr with 'or' and 'and' within Robert Kern <robert.kern@gmail.com> - 2013-06-14 11:14 +0100
Re: Eval of expr with 'or' and 'and' within Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-14 16:09 +0000
Re: Eval of expr with 'or' and 'and' within rusi <rustompmody@gmail.com> - 2013-06-14 09:21 -0700
Re: Eval of expr with 'or' and 'and' within Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-06-14 20:03 +0200
Re: Eval of expr with 'or' and 'and' within rusi <rustompmody@gmail.com> - 2013-06-14 11:37 -0700
Re: Eval of expr with 'or' and 'and' within Joshua Landau <joshua.landau.ws@gmail.com> - 2013-06-14 19:47 +0100
Re: Eval of expr with 'or' and 'and' within alex23 <wuwei23@gmail.com> - 2013-06-14 23:50 -0700
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 10:04 +0300
Re: Eval of expr with 'or' and 'and' within Denis McMahon <denismfmcmahon@gmail.com> - 2013-06-15 07:49 +0000
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 10:59 +0300
Re: Eval of expr with 'or' and 'and' within Grant Edwards <invalid@invalid.invalid> - 2013-06-14 14:49 +0000
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-14 18:16 +0300
Re: Eval of expr with 'or' and 'and' within Nobody <nobody@nowhere.com> - 2013-06-14 17:42 +0100
Re: Eval of expr with 'or' and 'and' within Grant Edwards <invalid@invalid.invalid> - 2013-06-14 19:30 +0000
Re: Eval of expr with 'or' and 'and' within Nobody <nobody@nowhere.com> - 2013-06-15 00:02 +0100
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 10:57 +0300
Re: Eval of expr with 'or' and 'and' within Michael Torrie <torriem@gmail.com> - 2013-06-14 10:29 -0600
Re: Eval of expr with 'or' and 'and' within Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-14 16:49 +0000
Re: Eval of expr with 'or' and 'and' within Michael Torrie <torriem@gmail.com> - 2013-06-14 11:28 -0600
Re: Eval of expr with 'or' and 'and' within MRAB <python@mrabarnett.plus.com> - 2013-06-14 18:49 +0100
Re: Eval of expr with 'or' and 'and' within Chris Angelico <rosuav@gmail.com> - 2013-06-15 03:56 +1000
Re: Eval of expr with 'or' and 'and' within Grant Edwards <invalid@invalid.invalid> - 2013-06-14 19:33 +0000
Re: Eval of expr with 'or' and 'and' within Chris Angelico <rosuav@gmail.com> - 2013-06-15 09:56 +1000
Re: Eval of expr with 'or' and 'and' within Nobody <nobody@nowhere.com> - 2013-06-15 00:09 +0100
Re: Eval of expr with 'or' and 'and' within Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-15 01:34 +0000
Re: Eval of expr with 'or' and 'and' within Cameron Simpson <cs@zip.com.au> - 2013-06-15 12:03 +1000
NANs [was Re: Eval of expr with 'or' and 'and' within] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-15 04:22 +0000
Re: Eval of expr with 'or' and 'and' within Chris Angelico <rosuav@gmail.com> - 2013-06-15 12:21 +1000
Re: Eval of expr with 'or' and 'and' within Nobody <nobody@nowhere.com> - 2013-06-15 00:06 +0100
Re: Eval of expr with 'or' and 'and' within MRAB <python@mrabarnett.plus.com> - 2013-06-15 01:26 +0100
Re: Eval of expr with 'or' and 'and' within Benjamin Kaplan <benjamin.kaplan@case.edu> - 2013-06-14 09:47 -0700
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-14 20:01 +0300
Re: Eval of expr with 'or' and 'and' within Robert Kern <robert.kern@gmail.com> - 2013-06-14 18:27 +0100
Re: Eval of expr with 'or' and 'and' within Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-06-14 22:05 +0300
Re: Eval of expr with 'or' and 'and' within Grant Edwards <invalid@invalid.invalid> - 2013-06-14 19:36 +0000
Re: Eval of expr with 'or' and 'and' within Cameron Simpson <cs@zip.com.au> - 2013-06-15 10:14 +1000
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 11:20 +0300
Re: Eval of expr with 'or' and 'and' within Lele Gaifax <lele@metapensiero.it> - 2013-06-15 11:48 +0200
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 16:24 +0300
Re: Eval of expr with 'or' and 'and' within Nick the Gr33k <support@superhost.gr> - 2013-06-15 16:28 +0300
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