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Python Object-Oriented Python Advanced Objects Multiplication

Incorrect code in __mul__ __rmul__ challenge.

Hi. I'm not too sure why this is incorrect, can anyone advise?

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):
        return self * other

2 Answers

Jennifer Nordell
Jennifer Nordell
Treehouse Teacher

Hi there, Jordan young ! Before you can multiply a string by a number, you need to first convert it to an int. So where you have self * other, you need int(self) * other.

Hope this helps! :sparkles:

Hi Jennifer, This does make sense.

However after doing that, I am returned with this error " Can't multiply a number with a NumString (i.e. 10 * NumString)"

my code update is as follows: def mul (self, other): return int(self) * other

def __rmmul__ (self, other):
    return int(self) * other

This was an especially confusing error as I thought that int placement converts the string like your message suggests.

Is there a mistake somewhere in the code above that I previously had used?

Jennifer Nordell
Jennifer Nordell
Treehouse Teacher

Hi again, Jordan young ! You have a typo in the definition of your method.

You typed:

def __rmmul__(self, other):

But you meant to type:

def __rmul__(self, other):

Note that your version contains two "m"s where as the correct version contains one "m" :smiley:

Hope this helps! :sparkles:

This is indeed solved.

Grrr don't you hate it when that happens?

Thank you :)