While loop help

[Larry Hudson]

On 04/09/2013 09:49 AM, thomasancilleri at gmail.com wrote:
> So what would be the proper way to perform a loop of this program. I still can't quite figure out the best way to do it.
>

My suggestion... (pseudocode)

#   Print a heading/introduction here
while True:
     #   Print menu, with an added selection to quit
     #   Get the user's choice (as an int)
     if choice == 1:
         #   Print prompt for this choice
         #   Enter the value (as float, not int.  Why limit your values to ints anyway?)
         #   Display the calculated result
     elif choice == 2:
         #   Same procedure as above
     elif ... etc
         #   etc
     elif choice == (value for quit):
         break    #   This breaks out of the while loop
     else:
         #   Invalid choice, print error message
#   End of loop

Further suggestion:
Since each of the choices use the same basic procedure, it could be written as a separate single 
function.  It would just need to be passed the appropriate prompt string(s) and conversion 
factor.  The results display _could_ be in this function also, but that would require passing 
even more strings.  It would probably be better to simply return the two values (the input value 
and the converted value) back to the calling block and print the results there.

Also, don't use the round function here, that does NOT guarantee it will be _printed_ to two 
decimal places.  Use string formatting in the print statements.  For example: (using your 
original variable names, and assuming they are now both floats)

old style:

     print '%.2f inches = %.2f meters' % (number, calc)

or new style:

     print '{:.2f} inches = {:.2f} meters'.format(number, calc)

You also mentioned that you don't like the editor you're using.  For a simple substitute you 
might try Idle (which normally comes with Python).  This gives you the advantage of an 
interactive environment as will as an editor.  There are many other choices, of course, but as a 
newbie you might find this more comfortable than what you're currently using.

I hope this jump-starts your thinking.  Keep at it, it's worth the effort.

      -=- Larry -=-