Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #27711

Re: Guarding arithmetic

Show all headers | View raw

On Thu, Aug 23, 2012 at 7:05 PM, Mark Carter <alt.mcarter@gmail.com> wrote:
> Suppose I want to define a function "safe", which returns the argument passed if there is no error, and 42 if there is one. So the setup is something like:
>
> def safe(x):
>    # WHAT WOULD DEFINE HERE?
>
> print safe(666) # prints 666
> print safe(1/0) # prints 42
>
> I don't see how such a function could be defined. Is it possible?

That can work ONLY if the division of 1/0 doesn't raise an exception.
This is why the concept of NaN exists; I'm not sure if there's a way
to tell Python to return NaN instead of bombing, but it's most likely
only possible with floating point, not integer.

However, there's an easier way.

try:
    print 1/0
except ZeroDivisionError:
    print 42

Catch the exception and do with it what you will.

ChrisA

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Guarding arithmetic Mark Carter <alt.mcarter@gmail.com> - 2012-08-23 02:05 -0700
  Re: Guarding arithmetic Chris Angelico <rosuav@gmail.com> - 2012-08-23 19:16 +1000
    Re: Guarding arithmetic Mark Carter <alt.mcarter@gmail.com> - 2012-08-23 02:22 -0700
    Re: Guarding arithmetic Chris Angelico <rosuav@gmail.com> - 2012-08-23 19:29 +1000
    Re: Guarding arithmetic Mark Carter <alt.mcarter@gmail.com> - 2012-08-23 02:22 -0700
  Re: Guarding arithmetic Laszlo Nagy <gandalf@shopzeus.com> - 2012-08-23 11:23 +0200
    Re: Guarding arithmetic Mark Carter <alt.mcarter@gmail.com> - 2012-08-23 02:47 -0700
    Re: Guarding arithmetic Mark Carter <alt.mcarter@gmail.com> - 2012-08-23 02:47 -0700
  Re: Guarding arithmetic Laszlo Nagy <gandalf@shopzeus.com> - 2012-08-23 11:28 +0200
  Re: Guarding arithmetic Chris Angelico <rosuav@gmail.com> - 2012-08-23 19:30 +1000
  Re: Guarding arithmetic Peter Otten <__peter__@web.de> - 2012-08-23 12:11 +0200
    Re: Guarding arithmetic rusi <rustompmody@gmail.com> - 2012-08-23 10:15 -0700
  Re: Guarding arithmetic Laszlo Nagy <gandalf@shopzeus.com> - 2012-08-23 13:01 +0200
  Re: Guarding arithmetic MRAB <python@mrabarnett.plus.com> - 2012-08-23 12:21 +0100
  Re: Guarding arithmetic Peter Otten <__peter__@web.de> - 2012-08-23 13:28 +0200
  Re: Guarding arithmetic Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-08-23 15:11 +0100
  Re: Guarding arithmetic Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-08-23 14:49 -0400
  Re: Guarding arithmetic Chris Angelico <rosuav@gmail.com> - 2012-08-24 07:48 +1000

csiph-web