这与imran和ralu的回答相似。它不使用生成器，而是使用闭包的递归:

def flatten_dict(d, separator='_'):
  final = {}
  def _flatten_dict(obj, parent_keys=[]):
    for k, v in obj.iteritems():
      if isinstance(v, dict):
        _flatten_dict(v, parent_keys + [k])
      else:
        key = separator.join(parent_keys + [k])
        final[key] = v
  _flatten_dict(d)
  return final

>>> print flatten_dict({'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y' : 10}}, 'd': [1, 2, 3]})
{'a': 1, 'c_a': 2, 'c_b_x': 5, 'd': [1, 2, 3], 'c_b_y': 10}

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}

这是一种“功能性的”、“单行程序”实现。它是递归的，基于条件表达式和字典理解。

def flatten_dict(dd, separator='_', prefix=''):
    return { prefix + separator + k if prefix else k : v
             for kk, vv in dd.items()
             for k, v in flatten_dict(vv, separator, kk).items()
             } if isinstance(dd, dict) else { prefix : dd }

测试:

In [2]: flatten_dict({'abc':123, 'hgf':{'gh':432, 'yu':433}, 'gfd':902, 'xzxzxz':{"432":{'0b0b0b':231}, "43234":1321}}, '.')
Out[2]: 
{'abc': 123,
 'gfd': 902,
 'hgf.gh': 432,
 'hgf.yu': 433,
 'xzxzxz.432.0b0b0b': 231,
 'xzxzxz.43234': 1321}

使用dict.popitem()在直接的嵌套列表类递归中:

def flatten(d):
    if d == {}:
        return d
    else:
        k,v = d.popitem()
        if (dict != type(v)):
            return {k:v, **flatten(d)}
        else:
            flat_kv = flatten(v)
            for k1 in list(flat_kv.keys()):
                flat_kv[k + '_' + k1] = flat_kv[k1]
                del flat_kv[k1]
            return {**flat_kv, **flatten(d)}

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)

这一变化扁平化嵌套字典，压缩键与max_level和自定义减速器。

  def flatten(d, max_level=None, reducer='tuple'):
      if reducer == 'tuple':
          reducer_seed = tuple()
          reducer_func = lambda x, y: (*x, y)
      else:
          raise ValueError(f'Unknown reducer: {reducer}')

      def impl(d, pref, level):
        return reduce(
            lambda new_d, kv:
                (max_level is None or level < max_level)
                and isinstance(kv[1], dict)
                and {**new_d, **impl(kv[1], reducer_func(pref, kv[0]), level + 1)}
                or {**new_d, reducer_func(pref, kv[0]): kv[1]},
                d.items(),
            {}
        )

      return impl(d, reducer_seed, 0)