local variable 'juveniles' referenced before assignment

[Alan Robinson]

On Wednesday, 13 January 2016 13:06:11 UTC, Peter Otten  wrote:
> Alan Robinson wrote:
> 
> > On Wednesday, 13 January 2016 12:32:51 UTC, Chris Angelico  wrote:
> >> On Wed, Jan 13, 2016 at 11:23 PM, Alan Robinson
> >> <arobinson at lordlawson.org.uk> wrote:
> >> > def menu():
> >> >     option = int(input("Please select an option: \n 1: Set Generation 0
> >> >     Values \n 2: View Generation 0 Values \n 3: Run Model \n 4: Print
> >> >     values"))
> >> >
> >> >     if option == 1:
> >> >         juveniles,adults,seniles = setGen()
> >> >     elif option == 2:
> >> >         displayGen()
> >> >     elif option == 3:
> >> >         runModel(juveniles,adults,seniles)
> >> >     elif option == 4:
> >> >         print(juveniles,adults,seniles)
> >> >     menu()
> >> >
> >> 
> >> This is a classic use of recursion instead of iteration. When you call
> >> menu() again, you're creating a completely new 'slot' for the new
> >> function; it has its own set of names. Assigning to names in one call
> >> of menu() has no effect on any other call.
> >> 
> >> Instead, look into the way a while loop works. You'll find that your
> >> code is simpler and clearer, plus your variables will stay set.
> >> 
> >> ChrisA
> > thanks I need the menu to run again not sure how to do that though
> 
> def menu():
>     option = 1 # make sure setGen is invoked on first iteration
>     while option: # choosing 0 ends the while loop
>         if option == 1:
>            juveniles, adults, seniles = setGen()
>         elif option == 2:
>            ...
>         option = int(input(...)) # choose option for the next iteration

that's really helpful I understand whats happening now I just need to work out how to do this loop as I am new it looks difficult to do here goes