local variable 'juveniles' referenced before assignment
Peter Otten
__peter__ at web.de
Wed Jan 13 08:05:39 EST 2016
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
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