Output with none, print(x) in function

[deanhystad]

I think putting a print statement in odd_numbers() is bad design. It makes the function useless. I cannot use your odd_numbers() to get a list of odd numbers for the program I am writing. I don't want the printing numbers side effect messing up the output in my program.

For something like this maybe I want a generator.

def odd_numbers(start=1, end=None):
    if start % 2 == 0:
        start += 1
    while True:
        if end and start > end:
             break
        yield start
        start += 2

# If I want to print odd numbers
print('Count from 11 to 21 by 2')
for x in odd_numbers(11, 21):
    print(x)

# If I want a list of odd nmbers
a = list(odd_numbers(1, 7))
b = [x for x in odd_numbers(13, 21)]
print('Combined lists =', a+b)

# Or an unknown number of odd numbers
odds_gen = odd_numbers()
odds = []
while sum(odds) < 100:
    odds.append(next(odds_gen))
print(f'sum{odds} = {sum(odds)}')

You would never do something like this for odd numbers. They are way too easy to generate ad hoc. But you might do this for a different sequence that is not so easy to generate and that might have several different uses.