Python's Magic Methods in Classes (Summary)

For me, the biggest take away is the understanding of ‘init()’ and the ‘str()’ dunder methods.

I created the Storage class without saving the ‘value’ attribute in the instance since it should have been created by the super().__new__(class, value).

class Storage(float):
    def __new__(cls, value, unit):
        instance = super().__new__(cls, value)
        instance.unit = unit
        return instance
    def __str__(self):
        return f'{super().__repr__()} {self.unit}'

When I created the object >>> storage_size = Storage(512, 'GB'), entering just storage_size in the repl, the value ‘512’ was printed out. So the value was available from the object. Using the print() function, the output was 5120 GB as per the __str__ method.

When I tried to create the __repr__ method in a similar fashion, I got a recursion error. With my modified class object, how do I get the underlying float value from the inherited class from the __repr__ method’s ‘self’ object. I thought that including an instance.value attribute was essentially duplicating the underlying float value provided by the inherited class.

Great course, Negar!! I like how you introduced and explained things. I have used some of these magic methods in the past, but will be using them more in the future. I look forward to more courses from you!