在python中覆盖+运算符,用于float + obj

a = 3 + 4.5
print(a)  # 输出：7.5

a = 3.0
b = "hello"
c = a + b  # 抛出TypeError异常，因为无法将字符串隐式转换为数字

class MyClass:
    def __init__(self, value):
        self.value = value

    def __add__(self, other):
        return self.value + other

a = MyClass(3.0)
b = "hello"
c = a + b
print(c)  # 输出：3.0hello