function in function [closed]

Answer 1

Your count_healthy() function doesn't return a value, so b is None. Since the function does a print, which is then followed by the print b, that explains the output of a None after the output from the function.

Basically, a function that is supposed to do a count probably shouldn't also be printing the result, but should instead return it so the caller can decide the result should be printed or handled differently.

Answer 2

You are trying to print result of functions

a = get_bad_results(test_results)
print a

b =count_healthy(all_results)
print b

By default functions return None

Answer 3

ok I fixed it but now

def get_bad_results(person_results):
        for i in person_results:
                if i[1]>i[3] or i[1]<i[2]:
                    return i[0]

test_results = [["White blood cells",8.5,2,7],
                ["Neutrophils",5.3,2.5,5],
                ["Red blood cells", 12.4, 9,15]]

a = get_bad_results(test_results)
print a

show White blood cells

instead of White blood cells, Neutrophils

Answer 4

Your function doesn't have a return statement, so it implicitly returns None.

Try adding a return statement and return the value that you want to be printed.

Answer 5

As you expect several results per call, it is the best to use a generator function:

def get_bad_results(person_results):
    for i in person_results:
        if i[1]>i[3] or i[1]<i[2]:
            yield i[0]

or a generator expression:

def get_bad_results(person_results):
    return (i[0] for i in person_results if i[1]>i[3] or i[1]<i[2])

so that

test_results = [["White blood cells",8.5,2,7],
                ["Neutrophils",5.3,2.5,5],
                ["Red blood cells", 12.4, 9,15]]

for i in get_bad_results(test_results):
    print i
print list(get_bad_results(test_results))
print ", ".join(get_bad_results(test_results))

gives the output

White blood cells
Neutrophils
['White blood cells', 'Neutrophils']
White blood cells, Neutrophils

For the other function, do

def count_healthy(all_results):
    counter = 0
    for i in all_results:
        if len(list(get_bad_results(i))) == 0:
            counter += 1
    return counter

or just

def count_healthy(all_results):
    return sum(1 for i in all_results if len(list(get_bad_results(i))) == 0)

---

Edit:

For many get_bad_results(), turning it into a list could be memory-intensive.

So instead of len(list(get_bad_results(i))) == 0 you could use

def has_results(it):
    """Returns True if the iterator it yields any items."""
    return next((True for _ in it), False)

and then

def count_healthy(all_results):
    return sum(1 for i in all_results if not has_results(get_bad_results(i)))