Question

Basic stuff I know…;-P But what is the best way to check if a function returns some values?

def hillupillu():
    a= None
    b="lillestalle"
    return a,b

if i and j in hillupillu(): #how can i check if i or j are empty? this is not doing it of course;-P
    print i,j 

Answer 1

If you meant that you can’t predict the number of return values of some function, then

i, j = hillupillu()

will raise a ValueError if the function doesn’t return exactly two values. You can catch that with the usual try construct:

try:
    i, j = hillupillu()
except ValueError:
    print("Hey, I was expecting two values!")

This follows the common Python idiom of “asking for forgiveness, not permission”. If hillupillu might raise a ValueError itself, you’ll want to do an explicit check:

r = hillupillu()
if len(r) != 2:  # maybe check whether it's a tuple as well with isinstance(r, tuple)
    print("Hey, I was expecting two values!")
i, j = r

If you meant that you want to check for None in the returned values, then check for None in (i, j) in an if-clause.