ahmet / Python-for-Data-Science

class calculator:
    """Compute a vector of numbers against a scalar.

    Every operation updates the vector held by the calculator and
    prints the result, so the operations can be chained.
    """

    def __init__(self, vector: list) -> None:
        """Build a calculator holding the vector to work on."""
        self.vector = vector

    def __add__(self, object) -> None:
        """Add the scalar to each value of the vector and print it."""
        self.vector = [value + object for value in self.vector]
        print(self.vector)

    def __mul__(self, object) -> None:
        """Multiply each value of the vector by the scalar and print it."""
        self.vector = [value * object for value in self.vector]
        print(self.vector)

    def __sub__(self, object) -> None:
        """Remove the scalar from each value of the vector and print it."""
        self.vector = [value - object for value in self.vector]
        print(self.vector)

    def __truediv__(self, object) -> None:
        """Divide each value of the vector by the scalar and print it.

        A division by zero is reported and leaves the vector untouched.
        """
        if object == 0:
            print("Error: division by zero is not allowed")
            return
        self.vector = [value / object for value in self.vector]
        print(self.vector)


def main() -> None:
    """Test the calculator against a scalar."""
    v1 = calculator([0.0, 1.0, 2.0, 3.0, 4.0, 5.0])
    v1 + 5
    print("---")
    v2 = calculator([0.0, 1.0, 2.0, 3.0, 4.0, 5.0])
    v2 * 5
    print("---")
    v3 = calculator([10.0, 15.0, 20.0])
    v3 - 5
    v3 / 5
    print("---")
    v3 / 0


if __name__ == "__main__":
    main()