AttributeError: 'tuple' object has no attribute

You return four variables s1,s2,s3,s4 and receive them using a single variable obj. This is what is called a tuple, obj is associated with 4 values, the values of s1,s2,s3,s4. So, use index as you use in a list to get the value you want, in order.

obj=list_benefits()
print obj[0] + " is a benefit of functions!"
print obj[1] + " is a benefit of functions!"
print obj[2] + " is a benefit of functions!"
print obj[3] + " is a benefit of functions!"

You're returning a tuple. Index it.

obj=list_benefits()
print obj[0] + " is a benefit of functions!"
print obj[1] + " is a benefit of functions!"
print obj[2] + " is a benefit of functions!"

Variables names are only locally meaningful.

Once you hit

return s1,s2,s3,s4

at the end of the method, Python constructs a tuple with the values of s1, s2, s3 and s4 as its four members at index 0, 1, 2 and 3 - NOT a dictionary of variable names to values, NOT an object with variable names and their values, etc.

If you want the variable names to be meaningful after you hit return in the method, you must create an object or dictionary.

class list_benefits(object):
    def __init__(self):
        self.s1 = "More organized code"
        self.s2 = "More readable code"
        self.s3 = "Easier code reuse"

def build_sentence():
        obj=list_benefits()
        print obj.s1 + " is a benefit of functions!"
        print obj.s2 + " is a benefit of functions!"
        print obj.s3 + " is a benefit of functions!"

print build_sentence()

I know it is late answer, maybe some other folk can benefit If you still want to call by "attributes", you could use class with default constructor, and create an instance of the class as mentioned in other answers

I am working in python flask: I had the same problem... There was a "," after I declared my my form variables; I am working with wtforms. That is what caused all the confusion