[Tutor] Exception Handling

[David]

Jervis Whitley wrote:
> 
> 
> On Wed, Dec 31, 2008 at 8:33 AM, David <david at abbottdavid.com 
> <mailto:david at abbottdavid.com>> wrote:
> 
>         On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:
> 
>              > On Mon, 29 Dec 2008 09:10:45 -0000
>              > "Alan Gauld" <alan.gauld at btinternet.com
>             <mailto:alan.gauld at btinternet.com>> wrote:
>              > >
> 
>                  >> "bob gailer" <bgailer at gmail.com
>                 <mailto:bgailer at gmail.com>> wrote
>                  >>

> Hi David,
> 
> If the user enters incorrect data for the month or day, a ValueError 
> will still be raised 
> on the conversion to integer.
> 
> I suggest that you wrap your request for user information in a function 
> that does the checking
> for you. You can re-use this function for each piece of integer 
> information you require from the user.
> 
> example:
> 
> import time
> 
> 
> class BadUserError(Exception):
>     pass
> 
> def get_integer(retrieve, question, attempts=3):
>     """ 
>     A small function to attempt to retrieve 
>     information from a user, given a prompt question.
> 
>     retrive - any function that will accept a string as an argument
>                 and return a string or otherwise response from the user.
>     question - a string type question that you would like to ask the user to
>                 respond to.
>     attempts[optional] - how many times the user can incorrectly
>                         enter data before the BadUserError is raised.
>     """
> 
>     while attempts > 0:
>         num = retrieve(question)
>         try:
>             # try casting the user input as an integer.
>             return int(num)
>         except ValueError:
>             print "Oops, You must enter a number!"
> 
>         attempts -= 1
>     raise BadUserError("Too many incorrect tries!") 
>

WOW, thanks Jervis, I had to edit some of my mistakes to get it to work 
right if your birthday is today. I also looked at tm_year, tm_mon, and 
tm_day. I still need to get it to prduce an error if the year is 0 or 
2009, the month is 0 or 13 and the day is 0 or 32.
david [06:56 PM] opteron ~ $ ./py_get_age.py
Please enter the date format as:  2008 12 30

What year were you born? 2010
What month were you born? 14
What day were you born? 34
You are -3 years old.

Here is a link to the current program;
http://dwabbott.com/code/
Thanks again everyone,
-david


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