2

我的代码(我无法使用“泡菜”):

class A(object):
    def __getstate__(self):
        print 'www'
        return 'sss'
    def __setstate__(self,d):
        print 'aaaa'

import pickle
a = A()
s = pickle.dumps(a)
e = pickle.loads(s)
print s,e

打印 :

www
aaaa
ccopy_reg
_reconstructor
p0
(c__main__
A
p1
c__builtin__
object
p2
Ntp3
Rp4
S'sss'
p5
b. <__main__.A object at 0x00B08CF0>

谁能告诉我怎么用。

4

3 回答 3

4

你想做什么?这个对我有用:

class A(object):
    def __init__(self):
        self.val = 100

    def __str__(self):
        """What a looks like if your print it"""
        return 'A:'+str(self.val)

import pickle
a = A()
a_pickled = pickle.dumps(a)
a.val = 200
a2 = pickle.loads(a_pickled)
print 'the original a'
print a
print # newline
print 'a2 - a clone of a before we changed the value'
print a2
print 

print 'Why are you trying to use __setstate__, not __init__?'
print

所以这将打印:

the original a
A:200

a2 - a clone of a before we changed the value
A:100

如果你需要设置状态:

class B(object):
    def __init__(self):
        print 'Perhaps __init__ must not happen twice?'
        print
        self.val = 100

    def __str__(self):
        """What a looks like if your print it"""
        return 'B:'+str(self.val)

    def __getstate__(self):
        return self.val

    def __setstate__(self,val):
        self.val = val

b = B()
b_pickled = pickle.dumps(b)
b.val = 200
b2 = pickle.loads(b_pickled)
print 'the original b'
print b
print # newline
print 'b2 - b clone of b before we changed the value'
print b2

打印:

Why are you trying to use __setstate__, not __init__?

Perhaps __init__ must not happen twice?

the original b
B:200

b2 - b clone of b before we changed the value
B:100
于 2010-01-07T10:29:31.067 回答
3

你可以pickle(意思是,这段代码可以正常工作)。你只是似乎得到了一个结果,你没想到。如果您期望相同的“输出”,请尝试:

import pickle
a = A()
s = pickle.dumps(a)
e = pickle.loads(s)
print s, pickle.dumps(e)

您的示例不是典型的“酸洗”示例。通常腌制的对象会永久保存在某个地方或通过网络发送。参见例如pickletest.py: http: //www.sthurlow.com/python/lesson10/

有高级用法pickling,例如参见 David Mertz XML 对象序列化文章:http ://www.ibm.com/developerworks/xml/library/x-matters11.html

于 2010-01-07T10:19:01.240 回答
0

简而言之,在您的示例中,e 等于 a。

不必关心这些字符串,你可以将这些字符串转储到任何地方,只要记住当你加载它们时,你又得到了'a'对象。

于 2010-01-07T10:16:59.427 回答