3
我试图学习描述符,并且被对象行为困惑 - 在下面的两个示例中,正如我理解的__init__
他们应该工作一样。有人可能会否认我,或者指出一个解释这一点的资源?使用__init__和设置类变量之间的区别
import math
class poweroftwo(object):
"""any time this is set with an int, turns it's value to a tuple of the int
and the int^2"""
def __init__(self, value=None, name="var"):
self.val = (value, math.pow(value, 2))
self.name = name
def __set__(self, obj, val):
print "SET"
self.val = (val, math.pow(val, 2))
def __get__(self, obj, objecttype):
print "GET"
return self.val
class powoftwotest(object):
def __init__(self, value):
self.x = poweroftwo(value)
class powoftwotest_two(object):
x = poweroftwo(10)
>>> a = powoftwotest_two()
>>> b = powoftwotest(10)
>>> a.x == b.x
>>> GET
>>> False #Why not true? shouldn't both a.x and b.x be instances of poweroftwo with the same values?
您可能希望在输出中包含类型(a.x)和类型(b.x)。 – 2009-06-19 17:05:57