python 是否有类似 reinterpret_cast 的机制？
嗯这里“类似”不是指和 C++ 的
reinterpret_cast
一模一样，是这个意思：
假设我有以下两个类：
class Point1(object):
def __init__(self, x, y):
(self._x, self._y) = (x, y)
def __str__(self):
return "(%d, %d)" % (x, y)
class Point2(object):
def __init__(self, y, x):
(self._x, self._y) = (x, y)
def __str__(self):
return "(%d, %d)" % (y, x)
那么是否有一个函数或运算符
reinterpret_cast
，使得若：
p = Point1(233, 2333)
pid = id(p)
pp = reinterpret_cast(p, Point2)
ppid = id(pp)
pps = str(pp)
t = type(pp)
那么
pid
和
ppid
相同，且
pps
是
'(2333, 233)'
以及
t
是
<class '__main__.Point2'>
lzcllyt
10 years, 3 months ago
Answers
# -*- coding:utf-8 -*-
class Point1(object):
def __init__(self, x, y):
(self._x, self._y) = (x, y)
def __str__(self):
return "(%d, %d)" % (self._x, self._y)
class Point2(object):
def __init__(self, y, x):
(self._x, self._y) = (x, y)
def __str__(self):
return "(%d, %d)" % (self._y, self._x)
def reinterpret_cast_like(instance,cls):
newinstance=instance
newinstance.__class__=cls
return newinstance
p1=Point1(1,2)
p2=reinterpret_cast_like(p1,Point2)
print id(p1),id(p2),p2,type(p2)
执行结果
39093968 39093968 (2, 1) <class '__main__.Point2'>
Process finished with exit code 0
未馴化D猫樣
answered 10 years, 3 months ago