def flatten(unflattened_dict, separator='_'):
    flattened_dict = {}

    for k, v in unflattened_dict.items():
        if isinstance(v, dict):
            sub_flattened_dict = flatten(v, separator)
            for k2, v2 in sub_flattened_dict.items():
                flattened_dict[k + separator + k2] = v2
        else:
            flattened_dict[k] = v

    return flattened_dict

使用flatdict库:

dic={'a': 1,
 'c': {'a': 2,
       'b': {'x': 5,
             'y' : 10}},
 'd': [1, 2, 3]}

import flatdict
f =  flatdict.FlatDict(dic,delimiter='_')
print(f)
#output
{'a': 1, 'c_a': 2, 'c_b_x': 5, 'c_b_y': 10, 'd': [1, 2, 3]}

这并不局限于字典，而是实现.items()的每个映射类型。进一步列表更快，因为它避免了if条件。尽管如此，功劳还是归于伊姆兰:

def flatten(d, parent_key=''):
    items = []
    for k, v in d.items():
        try:
            items.extend(flatten(v, '%s%s_' % (parent_key, k)).items())
        except AttributeError:
            items.append(('%s%s' % (parent_key, k), v))
    return dict(items)

使用发电机:

def flat_dic_helper(prepand,d):
    if len(prepand) > 0:
        prepand = prepand + "_"
    for k in d:
        i = d[k]
        if isinstance(i, dict):
            r = flat_dic_helper(prepand + k,i)
            for j in r:
                yield j
        else:
            yield (prepand + k,i)

def flat_dic(d):
    return dict(flat_dic_helper("",d))

d = {'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y' : 10}}, 'd': [1, 2, 3]}
print(flat_dic(d))


>> {'a': 1, 'c_a': 2, 'c_b_x': 5, 'd': [1, 2, 3], 'c_b_y': 10}

def flatten(dictionary, prefix = '', separator = '_'):
    out_dict = {}
    if type(dictionary) != dict:
        out_dict[prefix] = dictionary
        return out_dict
    elif dictionary is None:
        return None
    for k in dictionary.keys():
        if prefix:
            prefix_n = prefix + f'{separator}{k}'
        else:
            prefix_n = k
        out_dict.update(flatten_new(dictionary[k], prefix_n))
    return out_dict

输出:

{'a': 1, 'c_a': 2, 'c_b_x': 5, 'c_b_y': 10, 'd': [1, 2, 3]}

我正在考虑UserDict的一个子类来自动神奇地平键。

class FlatDict(UserDict):
    def __init__(self, *args, separator='.', **kwargs):
        self.separator = separator
        super().__init__(*args, **kwargs)

    def __setitem__(self, key, value):
        if isinstance(value, dict):
            for k1, v1 in FlatDict(value, separator=self.separator).items():
                super().__setitem__(f"{key}{self.separator}{k1}", v1)
        else:
            super().__setitem__(key, value)

‌ 优点是键可以动态添加，或者使用标准字典实例化，毫无疑问:

‌

>>> fd = FlatDict(
...    {
...        'person': {
...            'sexe': 'male', 
...            'name': {
...                'first': 'jacques',
...                'last': 'dupond'
...            }
...        }
...    }
... )
>>> fd
{'person.sexe': 'male', 'person.name.first': 'jacques', 'person.name.last': 'dupond'}
>>> fd['person'] = {'name': {'nickname': 'Bob'}}
>>> fd
{'person.sexe': 'male', 'person.name.first': 'jacques', 'person.name.last': 'dupond', 'person.name.nickname': 'Bob'}
>>> fd['person.name'] = {'civility': 'Dr'}
>>> fd
{'person.sexe': 'male', 'person.name.first': 'jacques', 'person.name.last': 'dupond', 'person.name.nickname': 'Bob', 'person.name.civility': 'Dr'}