Returning an element from list

Question

I'm trying to return an individual from the list that has fitness greater than or equal to 90. To do so I have to sort the list, but I think there is a better way.. how can I do this withought sorting. Like at the instant when the if condition becomes true print that perticular individual from the list.

    if any(individual.fitness >= 90 for individual in individuals):
        print('Threshold met!')
        individuals = sorted(
            individuals, key=lambda individual: individual.fitness, reverse=True)
        return individuals[0]

Just *any* individual in the list with fitness greater than 90? — juanpa.arrivillaga, Apr 01 '17 at 18:52
iterate through the list and print out when the fitness is 90 — Jeremy Fisher, Apr 01 '17 at 18:54
Possible duplicate of [Python: Find in list](http://stackoverflow.com/questions/9542738/python-find-in-list) — pvg, Apr 01 '17 at 18:56
@JeremyFisher the code already does. It just doesn't fish out the element it finds. — pvg, Apr 01 '17 at 18:58
it looks to me like you could just use `m = max(individuals, key=lambda x: x.fitness)` then only return `if m.fitness >= 90` — juanpa.arrivillaga, Apr 01 '17 at 18:58
@juanpa.arrivillaga that always succeeds, though. Edit: and requires an unnecessary full traversal — pvg, Apr 01 '17 at 18:59
@juanpa.arrivillaga yes any individual that has fitness greater than 90 — Eshan Pandey, Apr 01 '17 at 18:59
@EshanPandey not if there are no individuals with fitness greater than 90...? — juanpa.arrivillaga, Apr 01 '17 at 19:00
You really ought to take a look at http://stackoverflow.com/questions/9542738/python-find-in-list because it covers your case exactly - it tells you how to retrieve the first value found by the generator expression you already have. — pvg, Apr 01 '17 at 19:03

score 0 · Answer 1 · answered Apr 01 '17 at 22:56

0

Here you are :) :

for individual in individuals:
    if individual.fitness >= 90:
        print('Threshold met!')
        return individual
return None

answered Apr 01 '17 at 22:56

Claudio

7,474
3
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score -1 · Answer 2 · answered Apr 01 '17 at 19:10

list = [11, 35, 90, 95, 98, 89, 85]
list2 = [i for i in list if i>= 90]
print(list2)

Output of the above code is: [90, 95, 98]

It will return the list of values of your criteria. If you want to get every element individually, add these kines:

for individual in list2:
    print (individual)

These lines will give this output:

90 95 98

Returning an element from list

2 Answers2