是否有一种方法可以方便地在Python中定义类c结构?我厌倦了写这样的东西:

class MyStruct():
    def __init__(self, field1, field2, field3):
        self.field1 = field1
        self.field2 = field2
        self.field3 = field3

当前回答

每当我需要一个“行为像字典一样的即时数据对象”(我不会想到C结构体!),我就会想到这个可爱的hack:

class Map(dict):
    def __init__(self, **kwargs):
        super(Map, self).__init__(**kwargs)
        self.__dict__ = self

现在你可以说:

struct = Map(field1='foo', field2='bar', field3=42)

self.assertEquals('bar', struct.field2)
self.assertEquals(42, struct['field3'])

当你需要一个“不是类的数据包”的时候,非常方便,当命名元组是不可理解的……

其他回答

这里的一些答案非常详尽。我找到的最简单的选项是(from: http://norvig.com/python-iaq.html):)

class Struct:
    "A structure that can have any fields defined."
    def __init__(self, **entries): self.__dict__.update(entries)

初始化:

>>> options = Struct(answer=42, linelen=80, font='courier')
>>> options.answer
42

添加更多的:

>>> options.cat = "dog"
>>> options.cat
dog

编辑:对不起,没有看到这个例子已经进一步。

还可以按位置将初始化参数传递给实例变量

# Abstract struct class       
class Struct:
    def __init__ (self, *argv, **argd):
        if len(argd):
            # Update by dictionary
            self.__dict__.update (argd)
        else:
            # Update by position
            attrs = filter (lambda x: x[0:2] != "__", dir(self))
            for n in range(len(argv)):
                setattr(self, attrs[n], argv[n])

# Specific class
class Point3dStruct (Struct):
    x = 0
    y = 0
    z = 0

pt1 = Point3dStruct()
pt1.x = 10

print pt1.x
print "-"*10

pt2 = Point3dStruct(5, 6)

print pt2.x, pt2.y
print "-"*10

pt3 = Point3dStruct (x=1, y=2, z=3)
print pt3.x, pt3.y, pt3.z
print "-"*10

就我个人而言,我也喜欢这种变体。它扩展了@dF的答案。

class struct:
    def __init__(self, *sequential, **named):
        fields = dict(zip(sequential, [None]*len(sequential)), **named)
        self.__dict__.update(fields)
    def __repr__(self):
        return str(self.__dict__)

它支持两种初始化模式(可以混合使用):

# Struct with field1, field2, field3 that are initialized to None.
mystruct1 = struct("field1", "field2", "field3") 
# Struct with field1, field2, field3 that are initialized according to arguments.
mystruct2 = struct(field1=1, field2=2, field3=3)

而且,它打印得更好:

print(mystruct2)
# Prints: {'field3': 3, 'field1': 1, 'field2': 2}

你可以用元组来做很多你在C语言中使用结构体的事情(比如x,y坐标或RGB颜色)。

对于其他任何东西,你可以使用字典,或像这样的实用程序类:

>>> class Bunch:
...     def __init__(self, **kwds):
...         self.__dict__.update(kwds)
...
>>> mystruct = Bunch(field1=value1, field2=value2)

我认为“权威”的讨论在这里,在Python Cookbook的出版版本中。

我发现做到这一点的最好方法是使用自定义字典类,如本文所述:https://stackoverflow.com/a/14620633/8484485

如果需要iPython自动补全支持,只需像这样定义dir()函数:

class AttrDict(dict):
    def __init__(self, *args, **kwargs):
        super(AttrDict, self).__init__(*args, **kwargs)
        self.__dict__ = self
    def __dir__(self):
        return self.keys()

然后像这样定义你的伪结构(这个是嵌套的)

my_struct=AttrDict ({
    'com1':AttrDict ({
        'inst':[0x05],
        'numbytes':2,
        'canpayload':False,
        'payload':None
    })
})

然后你可以像这样访问my_struct中的值:

打印(my_struct.com1.inst)

= > [5]