Test for number?

[Neil Cerutti]

On 2006-09-04, George Sakkis <george.sakkis at gmail.com> wrote:
> Dr. Pastor wrote:
>> In the following code I would like to ascertain that x has/is
>> a number. What the simplest TEST should be? (Could not find
>> good example yet.)
>> ---
>> x=raw_input('\nType a number from 1 to 20')
>> if TEST :
>> 		Do_A
>> else:
>> 		Do_B
>> ---
>> Thanks for any guidance.
>
> x=raw_input('\nType a number from 1 to 20')
> try:
>     x = int(x)
>     if x<1 or x>20: raise ValueError()
> except ValueError:
>     Do_B
> else:
>     Do_A
>
> If you want to distinguish between the two error cases (not a
> number vs number not in [1,20]), handle the second one as
> "Do_C" instead of raising ValueError.

Is the original value of x available in Do_B and Do_A, or will it
have been clobbered before getting there?

-- 
Neil Cerutti