python2.7 - 如果使用Python创建非固定的类？

Question

python新手，搜索不到自己想搜索的内容。就比如从一个json配置文件中读取数据，然后根据这些数据，创建类的对象，然后调用这些对象的方法。而这个json配置文件的数据是可以自由设定的。可能有一组数据，对应一个...

扔个三星炸死你 · Answer

楼主是要动态创建对象吧。可以用exec 创建

    a = {"object1": {"attr1": "dawdad", "attr2": "dwagfreg"}, "object2": {"attr1": "45324523", "attr2": "45634"}}
    for obj_name in a:
        exec ('class %s(object):pass' % (obj_name))
        for attr in a[obj_name]:
            exec ('%s.%s="%s"' % (obj_name, attr, a[obj_name][attr]))
    print(object1.attr1)

输出 dawdad

你也可以用type 创建

class targetobject(object):
    def __init__(self, attr1, attr2):
        self.attr1 = attr1

    def func1(self):
        pass


if __name__ == '__main__':
    a = {"object1": {"attr1": "dawdad", "attr2": "dwagfreg"}, "object2": {"attr1": "45324523", "attr2": "45634"}}
    for obj_name in a:
        obj = type(str(obj_name), (targetobject,), a[obj_name])
        print(obj)
        print(obj.attr1)

滿天的星座 · Answer

Python 创建类的时候不一定要给齐成员（也就是说所有Python对象都是不固定的）

eg.

class A:
    pass
a.b = 1             # 可以通过
a.__dict__['c'] = 2 # 使用__dict__获取数据成员
print(a.b) # 1
print(a.c) # 2

所以只要读取Json，再给随便什么对象添加Json里对应的数据成员就好了

为情所困 · Answer

听楼主好像要的是这种结构：

# coding: utf-8

from collections import namedtuple


obj = {"object1":{"attr1":"dawdad","attr2":"dwagfreg"}, "object2":{"attr1":"45324523","attr2":"45634"}}

obj_insts = []
for obj_name in obj:
    obj_attr = obj[obj_name]
    attrs = obj_attr.keys()
    attr_values = obj_attr.values()
    Obj = namedtuple(obj_name, attrs)
    obj_insts.append(Obj(*attr_values))

print(obj_insts)
print(ibj_insts[0].attr1)
[object1(attr2='dwagfreg', attr1='dawdad'), object2(attr2='45634', attr1='45324523')]
dawdad

如果是配置文件，推荐用toml(https://github.com/toml-lang/...
安装python toml，就可以使用。

伊谢尔伦 · Answer

其实我觉得你应该是想将文件中的json数据,变成可以操作的对象, 就类似字典那样..看下json库是否满足要求吧:

cat 1.txt:
{"object1":{"attr1":"dawdad","attr2":"dwagfreg"},"object2":"attr1":"45324523","attr2":"45634"}}

# python交互shell
>>> import json
>>> a = json.load(open('1.txt'))
>>> a
{u'object1': {u'attr2': u'dwagfreg', u'attr1': u'dawdad'}, u'object2': {u'attr2': u'45634', u'attr1': u'45324523'}}
>>> a['object1']
{u'attr2': u'dwagfreg', u'attr1': u'dawdad'}