一尘不染

Python-如何使用点“。” 访问字典成员?

python

如何通过点“。”访问Python词典成员?

例如,mydict['val']我想写而不是写mydict.val

我也想以这种方式访问​​嵌套的字典。例如

mydict.mydict2.val 

将指

mydict = { 'mydict2': { 'val': ... } }

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2020-02-22

共2个答案

一尘不染

你可以使用我刚刚制作的此类来做。通过此类,你可以Map像其他字典(包括json序列化)一样使用该对象,也可以使用点符号。希望对你有所帮助:

class Map(dict):
    """
    Example:
    m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
    """
    def __init__(self, *args, **kwargs):
        super(Map, self).__init__(*args, **kwargs)
        for arg in args:
            if isinstance(arg, dict):
                for k, v in arg.iteritems():
                    self[k] = v

        if kwargs:
            for k, v in kwargs.iteritems():
                self[k] = v

    def __getattr__(self, attr):
        return self.get(attr)

    def __setattr__(self, key, value):
        self.__setitem__(key, value)

    def __setitem__(self, key, value):
        super(Map, self).__setitem__(key, value)
        self.__dict__.update({key: value})

    def __delattr__(self, item):
        self.__delitem__(item)

    def __delitem__(self, key):
        super(Map, self).__delitem__(key)
        del self.__dict__[key]

用法示例:

m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
# Add new key
m.new_key = 'Hello world!'
# Or
m['new_key'] = 'Hello world!'
print m.new_key
print m['new_key']
# Update values
m.new_key = 'Yay!'
# Or
m['new_key'] = 'Yay!'
# Delete key
del m.new_key
# Or
del m['new_key']
2020-02-22
一尘不染

我一直将其保存在util文件中。你也可以在自己的类中将其用作混合。

class dotdict(dict):
    """dot.notation access to dictionary attributes"""
    __getattr__ = dict.get
    __setattr__ = dict.__setitem__
    __delattr__ = dict.__delitem__

mydict = {'val':'it works'}
nested_dict = {'val':'nested works too'}
mydict = dotdict(mydict)
mydict.val
# 'it works'

mydict.nested = dotdict(nested_dict)
mydict.nested.val
# 'nested works too'
2020-02-22