如何对嵌套字典进行排序？

def sort_nested_dict(nested_dict):
    flattened_dict = []
    
    # 提取键值对并展平字典
    for key, value in nested_dict.items():
        if isinstance(value, dict):
            # 如果值仍为字典，则递归展平
            flattened_dict.extend([(key + '.' + k, v) for k, v in sort_nested_dict(value)])
        else:
            flattened_dict.append((key, value))
    
    # 根据键进行排序
    sorted_dict = sorted(flattened_dict, key=lambda x: x[0])
    
    # 重新构建嵌套字典
    nested_sorted_dict = {}
    for key_value in sorted_dict:
        keys = key_value[0].split('.')
        current_dict = nested_sorted_dict
        
        for i, key in enumerate(keys):
            if i == len(keys) - 1:
                current_dict[key] = key_value[1]
            else:
                if key not in current_dict:
                    current_dict[key] = {}
                current_dict = current_dict[key]
    
    return nested_sorted_dict

nested_dict = {
    'b': 2,
    'a': {
        'c': 1,
        'd': 3,
        'b': {
            'e': 5,
            'f': 4
        }
    }
}

sorted_nested_dict = sort_nested_dict(nested_dict)
print(sorted_nested_dict)

{'a': {'b': {'e': 5, 'f': 4}, 'c': 1, 'd': 3}, 'b': 2}