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Groups > comp.lang.python > #104560
| From | Gregory Ewing <greg.ewing@canterbury.ac.nz> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Simple exercise |
| Date | 2016-03-11 12:24 +1300 |
| Message-ID | <dkee0qF5s1dU1@mid.individual.net> (permalink) |
| References | <mailman.117.1457600573.15725.python-list@python.org> |
Rodrick Brown wrote:
> if m.group(1) not in od.keys():
> od[m.group(1)] = int(m.group(2))
> else:
> od[m.group(1)] += int(od.get(m.group(1),0))
Others have pointed out what's wrong with this, but here's
a general tip: Don't repeat complicated subexpressions
such as m.group(1). Doing so makes the code hard to read
and therefore hard to spot errors in (and less efficient
as well, although that's a secondary consideration).
Instead, pull them out and give them meaningful names.
Doing so with the above code gives:
name = m.group(1)
value = m.group(2)
if name not in od.keys():
od[name] = int(value)
else:
od[name] += int(od.get(name, 0))
Now it's a lot eaier to see that you haven't used the
value anywhere in the second case, which should alert
you that something isn't right.
--
Greg
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Simple exercise Rodrick Brown <rodrick.brown@gmail.com> - 2016-03-10 04:02 -0500
Re: Simple exercise Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-10 11:30 +0100
Re: Simple exercise Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-10 12:07 +0100
Re: Simple exercise Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-10 17:05 +0100
Re: Simple exercise Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-10 17:08 +0100
Re: Simple exercise Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-03-11 12:24 +1300
Re: Simple exercise Chris Angelico <rosuav@gmail.com> - 2016-03-11 10:38 +1100
Re: Simple exercise BartC <bc@freeuk.com> - 2016-03-11 00:05 +0000
Re: Simple exercise Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-11 01:21 +0000
Re: Simple exercise BartC <bc@freeuk.com> - 2016-03-11 01:45 +0000
Re: Simple exercise Larry Martell <larry.martell@gmail.com> - 2016-03-10 20:53 -0500
Re: Simple exercise "Martin A. Brown" <martin@linux-ip.net> - 2016-03-10 17:56 -0800
Re: Simple exercise Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-11 02:03 +0000
Re: Simple exercise BartC <bc@freeuk.com> - 2016-03-11 02:18 +0000
Re: Simple exercise Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 07:35 -0700
Re: Simple exercise Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2016-03-14 15:06 +0000
Re: Simple exercise Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 09:00 -0700
Re: Simple exercise Steven D'Aprano <steve@pearwood.info> - 2016-03-15 10:59 +1100
Re: Simple exercise Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-15 07:26 +0200
Re: Simple exercise Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-03-15 19:39 +1100
Re: Simple exercise Chris Angelico <rosuav@gmail.com> - 2016-03-15 19:53 +1100
Re: Simple exercise Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-15 11:04 +0200
Re: Simple exercise Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2016-03-15 11:09 +0000
Re: Simple exercise Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-14 09:16 -0600
Re: Simple exercise Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 09:11 -0700
Re: Simple exercise Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-14 15:23 +0000
Re: Simple exercise Peter Otten <__peter__@web.de> - 2016-03-14 17:00 +0100
Re: Simple exercise Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-11 02:05 +0000
Re: Simple exercise Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 07:07 -0700
Re: Simple exercise Larry Martell <larry.martell@gmail.com> - 2016-03-14 10:13 -0400
Re: Simple exercise alister <alister.ware@ntlworld.com> - 2016-03-14 14:18 +0000
Re: Simple exercise Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 08:22 -0700
Re: Simple exercise MRAB <python@mrabarnett.plus.com> - 2016-03-14 15:57 +0000
Re: Simple exercise Chris Kaynor <ckaynor@zindagigames.com> - 2016-03-10 18:14 -0800
Re: Simple exercise boffi <boffi@casa.sua> - 2016-03-17 22:28 +0100
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