Calculate attribute if it doesn't exist

Question

I am trying to access an attribute that shouldn\'t be created in the __init__ method of my class but can be calculated by calling another method. I am trying to

Answer 1

You want to use the @property decorator. Create a method, that will be accessed like a normal attribute, that does lazy computation:

class SampleObject:

    def __init__(self):
        # ...
        self._total = None

    @property
    def total(self):
        """Compute or return the _total attribute."""
        if self._total is None:
            self.compute_total()

        return self._total