我的数据结构如下:

user = UserTuple(
    name=u'Anakin', surname=u'Skywalker', birthdate=datetime.date(1981, 7, 25),
    profile=ProfileTuple(avatar=u'http://localhost/profile.jpg')
)

我想用msgpack python模块打包这些数据但是msgpack将namedtuples转换为list。有可能像pickle/cpickle那样用msgpack打包数据并保留namedtuples?

最佳答案

您需要有最新的msgpack-python版本。v0.4.7不起作用。(当前必须从主分支安装)。

import msgpack
from collections import namedtuple

User = namedtuple('User', ['name', 'profile'])
Profile = namedtuple('Profile', ['avatar'])

def ext_pack(x):
    if isinstance(x, User):
        return msgpack.ExtType(1, msgpack.packb([x[0], x[1]], default=ext_pack, strict_types=True))
    elif isinstance(x, Profile):
        return msgpack.ExtType(2, msgpack.packb(x[0], default=ext_pack, strict_types=True))
    return x

def ext_unpack(code, data):
    if code == 1:
        name, profile = msgpack.unpackb(data, ext_hook=ext_unpack)
        return User(name, profile)
    elif code == 2:
        avatar = msgpack.unpackb(data, ext_hook=ext_unpack)
        return Profile(avatar)
    return msgpack.ExtType(code, data)

x = User("me", Profile(234))
s = msgpack.packb([x, [1, x]], default=ext_pack, strict_types=True)
msgpack.unpackb(s, ext_hook=ext_unpack)
>>> [User(name='me', profile=Profile(avatar=234)),
 [1, User(name='me', profile=Profile(avatar=234))]]

这里我们分别将UserProfile标记为类型代码1、2或者,可以将所有namedtuple视为同一类型代码,并将实际类型存储在数据字段中。

关于python - 将msgpack-python与嵌套namedtuples一起使用,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/35863822/

10-10 06:03