[Tutor] Help With Code

[Alan Gauld]

On 01/05/14 01:18, jordan smallwood wrote:
> Hey there,
>
> I have this code below (in to cm conversion) and I want to have the user
> try again if they enter in a non integer. What am I missing:

A loop.

There is a common pattern or idiom in Pytthon:

while True:
     get input
     if input ok:
        break  # exits the loop
     else:
        print error   # and go round the loop again

So in your case it will look like this:


while True:
> try:
>      value = float(raw_input('Please enter a number: '))
        break     # only gets here if no error
> except ValueError:
>      print "Not a valid number."

Those two extra lines are all you need.

HTH
-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.flickr.com/photos/alangauldphotos