浅谈Python魔法方法

>>> dir(int)
['__abs__', '__add__', '__and__', 
'__bool__', '__ceil__', '__len__', 
'__delattr__', '__dir__', '__divmod__', 
'__doc__', '__eq__', '__float__', ...]

>>> nums = [1, 2, 3]
>>> nums[0]
1
>>> nums.__getitem__(0)
1

>>> len(nums)
3
>>> nums.__len__()
3

class ToolMan(object):

    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __len__(self):
        return len(self.name)

    def __str__(self):
        return "你好, 打工人!"

    def __add__(self, other):
        # 将两个ToolMan的年龄加起来
        return self.age + other.age

    def __mul__(self, other):
        # 将两个 ToolMan 的年龄相乘
        return self.age * other.age

    def __ge__(self, other):
        # 对比连个 ToolMan 的年龄
        return self.age >= other.age

>>> tool_man1 = ToolMan("打工人1", 20)
>>> tool_man2 = ToolMan("打工人2", 25)
>>> print(tool_man1)
你好, 打工人!
>>> tool_man1 + tool_man2
45
>>> tool_man1 * tool_man2
500
>>> tool_man1 >= tool_man2
False