Python中常见的一些魔法方法及其用途

class Vector:
    def __init__(self, x=0, y=0):
        self.x = x
        self.y = y

    def __str__(self):
        return f'Vector({self.x}, {self.y})'

    def __repr__(self):
        return f'Vector(x={self.x}, y={self.y})'

    def __add__(self, other):
        return Vector(self.x + other.x, self.y + other.y)

    def __sub__(self, other):
        return Vector(self.x - other.x, self.y - other.y)

    def __mul__(self, scalar):
        return Vector(self.x * scalar, self.y * scalar)

    def __truediv__(self, scalar):
        if scalar != 0:
            return Vector(self.x / scalar, self.y / scalar)
        else:
            raise ValueError("Cannot divide by zero")

    def __eq__(self, other):
        return self.x == other.x and self.y == other.y

    def __lt__(self, other):
        return (self.x**2 + self.y**2) < (other.x**2 + other.y**2)

    def __gt__(self, other):
        return (self.x**2 + self.y**2) > (other.x**2 + other.y**2)

    def __getitem__(self, index):
        if index == 0: return self.x
        elif index == 1: return self.y
        else: raise IndexError("Index out of range")

    def __setitem__(self, index, value):
        if index == 0: self.x = value
        elif index == 1: self.y = value
        else: raise IndexError("Index out of range")

    def __len__(self):
        return 2  # Since our vector is always a 2D vector

    def __iter__(self):
        yield self.x
        yield self.y

    def __enter__(self):
        print("Entering context")
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        print("Exiting context")
        # Handle exception if any, cleanup resources, etc.