sys.argv and while loop

[Christopher Myers]

Julia Bell wrote:
> 
> Thanks for all of the advice.  I'm converting from perl, so I'm not used to
> thinking about the difference between a string and a number in general.
> 
> (We are planning to upgrade our version of python in the next few months.)
> 
> Now that I know I have to worry about type, what is the best way to determine
> if a string is convertible to a number (integer or float)?
> 
> If I use string.atoi(variable) or string.atof(variable), but variable cannot
> be converted to an integer or float, I get an error.  I'm just learning about
> catching exceptions, so I think I could figure out how to catch the error and
> do something appropriate if that's the recommended approach.  But, is there a
> better way (perform the test before trying to do the conversion)?
> 
> Julia Bell
> 

I recommend something like the following (obviously commenting and
uncommenting where appropriate to test):

str="3.14159"
#str="10000"
#str="foo"

try:
    num=string.atoi(str)
except ValueError:
    try:
        num=string.atof(str)
    except:
	num=str

if type(num) == type(1.0):
    print "Do float stuff in here"
elif type(num) == type(1):
    print "Do int stuff in here"
else:
    print "Value does not convert to a number"


I'd be very interested to see if there's a simpler way, though.

-- 
Christopher Myers, Graduate Software Developer 
Ingenta, Inc.
12 Bassett St.
Providence, RI  02903
ph:  401.331.2014 x 102
em:  chris.myers at ingenta.com
aim: chrismyers001