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Groups > comp.lang.python > #73398

Re: how to check if a value is a floating point or not

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Nicholas Cannon <nicholascannon1@gmail.com> writes:

> #checks if the user input is an integer value
> def checkint(a):
> 	if a.isnumeric():
> 		return True
> 	else:
> 		if a.isalpha():
> 			return False
> 		else:
> 			return True

What code will be using this function? Why would that not be better
replaced with a ‘try … except’ construction?

That is, don't do this (Look Before You Leap)::

    foo = get_a_string()
    if checkint(foo):
        bar = int(foo)
    else:
        bar = None

Instead, do this (Easier to Ask Forgiveness than Permission)::

    foo = get_a_string()
    try:
        bar = int(foo)
    except ValueError:
        bar = None

If you need to create an integer based on a string, just do it, and
handle the exception (if any) at an appropriate level.

> There is one annoying error doing it this way and that is if you enter
> 12.ab or ab.12 it will say that it is okay. Still working on this so
> this should get sorted out soon.

You are re-inventing a wheel (the ‘int’ callable) which already does all
of that properly. Make use of it, and your frustration will be reduced.

-- 
 \     “It is far better to grasp the universe as it really is than to |
  `\    persist in delusion, however satisfying and reassuring.” —Carl |
_o__)                                                            Sagan |
Ben Finney

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how to check if a value is a floating point or not nicholascannon1@gmail.com - 2014-06-18 22:53 -0700
  Re: how to check if a value is a floating point or not Gary Herron <gary.herron@islandtraining.com> - 2014-06-18 23:22 -0700
  Re: how to check if a value is a floating point or not Nicholas Cannon <nicholascannon1@gmail.com> - 2014-06-18 23:48 -0700
    Re: how to check if a value is a floating point or not Ben Finney <ben@benfinney.id.au> - 2014-06-19 17:19 +1000
    Re: how to check if a value is a floating point or not Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-19 01:23 -0600
    Re: how to check if a value is a floating point or not Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-19 01:37 -0600
  Re: how to check if a value is a floating point or not Sturla Molden <sturla.molden@gmail.com> - 2014-06-19 13:46 +0000
  Re: how to check if a value is a floating point or not Nicholas Cannon <nicholascannon1@gmail.com> - 2014-06-19 23:14 -0700
    Re: how to check if a value is a floating point or not Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-20 00:22 -0600
    Re: how to check if a value is a floating point or not Sturla Molden <sturla.molden@gmail.com> - 2014-06-20 13:16 +0000
    Re: how to check if a value is a floating point or not Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-06-20 14:40 +0100
      Re: how to check if a value is a floating point or not Grant Edwards <invalid@invalid.invalid> - 2014-06-20 14:28 +0000
        Re: how to check if a value is a floating point or not alister <alister.nospam.ware@ntlworld.com> - 2014-06-20 15:15 +0000
        Re: how to check if a value is a floating point or not Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-20 09:44 -0600

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