Is it possible to create an attribute (read only!) that returns the size of a matrix or a vector, using the @property decorator?

Question

As in the question, I wonder how (if I can) I can create an attribute that gives me the matrix size, but I want to do it with the property decorator.

in this example, is it possible to use such a decorator?

class Matrix:
    def __init__(self, m, n, init=True):
        if init:
            self.rows = [[0] * n for x in range(m)]
        else:
            self.rows = []
        self.m = m
        self.n = n


    def __getitem__(self, idx):
        return self.rows[idx]

    def __setitem__(self, idx, item):
        self.rows[idx] = item

I'm still exploring the syntax, and i'd like some advice on doing this.

Answer 1

What you want to do is very simple — textbook trivial — so it's unclear what "advice" you want. Stack Overflow is not intended to replace existing tutorials or documentation. See How much research effort is expected of Stack Overflow users?.

class Matrix:
    def __init__(self, m, n, init=True):
        if init:
            self.rows = [[0] * n for x in range(m)]
        else:
            self.rows = []
        self.m = m
        self.n = n

    def __getitem__(self, idx):
        return self.rows[idx]

    def __setitem__(self, idx, item):
        self.rows[idx] = item

    @property
    def size(self):
        return self.m * self.n


if __name__ == '__main__':

    mat = Matrix(3, 3)
    print(mat.size)  # -> 9