Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Object-Oriented Python Advanced Objects Multiplication

Lucas Diz
Lucas Diz
4,804 Points
Posted by Lucas Diz
Lucas Diz
4,804 Points

Why sometimes it uses self.value and other uses, self * other. Didn't get this part.

def iadd(self, other): self.value = self + other return self.value

def __mul__(self, other):
    return self * other 

def __rmul__(self, other):
    self.value = self * other 
    return self.value
numstring.py 
class NumString:
    def __init__(self, value):
        self.value = str(value)

    def __str__(self):
         return self.value

    def __int__(self):
        return int(self.value)

    def __float__(self):
        return float(self.value)

    def __add__(self, other):
        if '.' in self.value:
            return float(self) + other
        return int(self) + other

    def __radd__(self, other):
        return self + other

    def __iadd__(self, other):
        self.value = self + other
        return self.value

    def __mul__(self,other):
        return self * other

    def __rmul__(self,other):
        self.value = self * other
        return self.value

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Using "self.value" gives direct access to the value stored in the instance. Using just "self" causes another of the "magic" methods to be invoked to handle the operation.