Test for number?

[Helmut Jarausch]

Tim Williams wrote:
> On 04/09/06, Dr. Pastor <elpX at adsihqx.com> 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
>> ---
> 
> Something simple like the following might help,
> 
>>>> def numtest():
> ...     x=raw_input('\nType a number from 1 to 20')
> ...     try:
> ...         x=int(x)
> ...         print x, "is a number between 1 & 20 "
> ...     except:
> ...         print x, "is not a number"
> ...
>>>> numtest()   # enter 1
> 1 is a number between 1 & 20
>>>> numtest()  #  enter "f"
> f is not a number
> 
> its not a final solution though,  think input = -2, 5.5  or 21
> 

One step further

try:
    eval(x+'0')
....


-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany