iteration stops

[jefsummers]

ok, this should work. See comments

list_nums= [i for i in range(15)] #your line
def fn(ln): #ln will be list_nums but less confusing scope
    output = [] #because you want all the numbers at once
    for i in ln: #proper for loop. Anything with range(len(anything)) there is a better way
        if i<9: 
            output.append(i) #add to list
    return output #this is what you return, not a single value
print(fn(list_nums))