对象字面量是Pythonic吗？

Question

JavaScript有对象字面量，例如

var p = {
  name: "John Smith",
  age:  23
}

而.NET有匿名类型，例如

var p = new { Name = "John Smith", Age = 23}; // C#

在Python中，可以通过(Ab)使用命名参数来模拟类似的东西：

class literal(object):
    def __init__(self, **kwargs):
        for (k,v) in kwargs.iteritems():
            self.__setattr__(k, v)
    def __repr__(self):
        return 'literal(%s)' % ', '.join('%s = %r' % i for i in sorted(self.__dict__.iteritems()))
    def __str__(self):
        return repr(self)

用法：

p = literal(name = "John Smith", age = 23)
print p       # prints: literal(age = 23, name = 'John Smith')
print p.name  # prints: John Smith

但是这种代码被认为是Pythonic式的吗？

Answer 1

您是否考虑过使用named tuple

使用你的口述符号

>>> from collections import namedtuple
>>> L = namedtuple('literal', 'name age')(**{'name': 'John Smith', 'age': 23})

或关键字参数

>>> L = namedtuple('literal', 'name age')(name='John Smith', age=23)
>>> L
literal(name='John Smith', age=23)
>>> L.name
'John Smith'
>>> L.age
23

可以很容易地将此行为封装到一个函数中

def literal(**kw):
    return namedtuple('literal', kw)(**kw)

等效于lambda的将是

literal = lambda **kw: namedtuple('literal', kw)(**kw)

但就我个人而言，我认为给“匿名”函数命名是愚蠢的

Answer 2

为什么不直接用字典呢？

p = {'name': 'John Smith', 'age': 23}

print p
print p['name']
print p['age']

Answer 3

来自ActiveState

class Bunch:
    def __init__(self, **kwds):
        self.__dict__.update(kwds)

# that's it!  Now, you can create a Bunch
# whenever you want to group a few variables:

point = Bunch(datum=y, squared=y*y, coord=x)

# and of course you can read/write the named
# attributes you just created, add others, del
# some of them, etc, etc:
if point.squared > threshold:
    point.isok = 1