使用object时的AttributeError .__ setattr__

Question

最后三行出了什么问题？

class FooClass(object):
    pass 
bar1 = object() 
bar2 = object() 
bar3 = object() 
foo1 = FooClass() 
foo2 = FooClass() 
foo3 = FooClass() 
object.__setattr__(foo1,'attribute','Hi')
foo2.__setattr__('attribute','Hi')
foo3.attribute = 'Hi'
object.__setattr__(bar1,'attribute','Hi')
bar2.attribute = 'Hi'
bar3.attribute = 'Hi'

我需要一个具有单个属性的对象（比如foo）我应该为它定义一个类（如FooClass）吗？

Answer 1

object是built-in type，因此您无法覆盖其实例的属性和方法。

也许您只想要一个dictionary或collections.NamedTuples：

>>> d = dict(foo=42)
{'foo': 42}
>>> d["foo"]
42

>>> from collections import namedtuple
>>> Point = namedtuple('Point', ['x', 'y'], verbose=True)
>>> p = Point(11, y=22)     # instantiate with positional or keyword arguments
>>> p[0] + p[1]             # indexable like the plain tuple (11, 22) 33
>>> x, y = p                # unpack like a regular tuple
>>> x, y (11, 22)
>>> p.x + p.y               # fields also accessible by name 33
>>> p                       # readable __repr__ with a name=value style Point(x=11, y=22)

Answer 2

您无法向object()添加新属性，只能添加子类。

尝试collections.NamedTuple s。

此外，代替object.__setattr__(foo1,'attribute','Hi')，setattr(foo1, 'attribute', 'Hi')会更好。