我自己是一个相对的python新手，但过去几周我一直在使用嵌套字典，这就是我想到的。

你应该尝试使用堆栈。将根字典中的键变成一个列表的列表:

stack = [ root.keys() ]     # Result: [ [root keys] ]

按照从最后到第一个的相反顺序，查找字典中的每个键，看看它的值是否(也是)一个字典。如果不是，打印密钥，然后删除它。但是，如果键的值是一个字典，则打印该键，然后将该值的键附加到堆栈的末尾，并以相同的方式开始处理该列表，对每个新的键列表进行递归重复。

如果每个列表中第二个键的值是一个字典，那么在几轮之后，你会得到这样的结果:

[['key 1','key 2'],['key 2.1','key 2.2'],['key 2.2.1','key 2.2.2'],[`etc.`]]

这种方法的优点是缩进只是\t乘以堆栈的长度:

indent = "\t" * len(stack)

缺点是为了检查每个键，你需要散列到相关的子字典，尽管这可以通过列表理解和简单的for循环轻松处理:

path = [li[-1] for li in stack]
# The last key of every list of keys in the stack

sub = root
for p in path:
    sub = sub[p]


if type(sub) == dict:
    stack.append(sub.keys()) # And so on

注意，这种方法将要求清除尾随的空列表，并删除后跟空列表的任何列表中的最后一个键(当然，这可能会创建另一个空列表，等等)。

还有其他方法来实现这个方法，但希望这能给你一个基本的想法。

编辑:如果您不想进行所有这些操作，pprint模块将以良好的格式打印嵌套字典。

这是我在编写一个需要在.txt文件中编写字典的类时想到的:

@staticmethod
def _pretty_write_dict(dictionary):

    def _nested(obj, level=1):
        indentation_values = "\t" * level
        indentation_braces = "\t" * (level - 1)
        if isinstance(obj, dict):
            return "{\n%(body)s%(indent_braces)s}" % {
                "body": "".join("%(indent_values)s\'%(key)s\': %(value)s,\n" % {
                    "key": str(key),
                    "value": _nested(value, level + 1),
                    "indent_values": indentation_values
                } for key, value in obj.items()),
                "indent_braces": indentation_braces
            }
        if isinstance(obj, list):
            return "[\n%(body)s\n%(indent_braces)s]" % {
                "body": "".join("%(indent_values)s%(value)s,\n" % {
                    "value": _nested(value, level + 1),
                    "indent_values": indentation_values
                } for value in obj),
                "indent_braces": indentation_braces
            }
        else:
            return "\'%(value)s\'" % {"value": str(obj)}

    dict_text = _nested(dictionary)
    return dict_text

现在，如果我们有一个这样的字典:

some_dict = {'default': {'ENGINE': [1, 2, 3, {'some_key': {'some_other_key': 'some_value'}}], 'NAME': 'some_db_name', 'PORT': '', 'HOST': 'localhost', 'USER': 'some_user_name', 'PASSWORD': 'some_password', 'OPTIONS': {'init_command': 'SET foreign_key_checks = 0;'}}}

我们这样做:

print(_pretty_write_dict(some_dict))

我们得到:

{
    'default': {
        'ENGINE': [
            '1',
            '2',
            '3',
            {
                'some_key': {
                    'some_other_key': 'some_value',
                },
            },
        ],
        'NAME': 'some_db_name',
        'OPTIONS': {
            'init_command': 'SET foreign_key_checks = 0;',
        },
        'HOST': 'localhost',
        'USER': 'some_user_name',
        'PASSWORD': 'some_password',
        'PORT': '',
    },
}

你可以通过PyYAML尝试YAML。它的输出可以微调。我建议从以下开始:

print(yaml.dump(data, allow_unicode=True, default_flow_style=False))

结果非常易读;如果需要，还可以解析回Python。

编辑:

例子:

>>> import yaml
>>> data = {'a':2, 'b':{'x':3, 'y':{'t1': 4, 't2':5}}}
>>> print(yaml.dump(data, default_flow_style=False))
a: 2
b:
  x: 3
  y:
    t1: 4
    t2: 5

例如，Pout可以漂亮地打印你扔给它的任何东西(借用另一个答案的数据):

data = {'a':2, 'b':{'x':3, 'y':{'t1': 4, 't2':5}}}
pout.vs(data)

将导致输出打印到屏幕上:

{
    'a': 2,
    'b':
    {
        'y':
        {
            't2': 5,
            't1': 4
        },
        'x': 3
    }
}

或者你可以返回对象的格式化字符串输出:

v = pout.s(data)

它的主要用途是调试，因此它不会阻塞对象实例或任何东西，它处理unicode输出，如你所期望的，在python 2.7和3中工作。

披露:我是撅嘴的作者和维护者。

我用了你们教我的东西加上装饰器的力量来重载经典的打印功能。只要根据需要改变缩进即可。我把它作为一个主旨在github，以防你想要星(保存)它。

def print_decorator(func):
    """
    Overload Print function to pretty print Dictionaries 
    """
    def wrapped_func(*args,**kwargs):
        if isinstance(*args, dict):
            return func(json.dumps(*args, sort_keys=True, indent=2, default=str))
        else:
            return func(*args,**kwargs)
    return wrapped_func
print = print_decorator(print)

现在就像往常一样使用打印。

这里有一些东西可以打印任何类型的嵌套字典，同时跟踪“父”字典。

dicList = list()

def prettierPrint(dic, dicList):
count = 0
for key, value in dic.iteritems():
    count+=1
    if str(value) == 'OrderedDict()':
        value = None
    if not isinstance(value, dict):
        print str(key) + ": " + str(value)
        print str(key) + ' was found in the following path:',
        print dicList
        print '\n'
    elif isinstance(value, dict):
        dicList.append(key)
        prettierPrint(value, dicList)
    if dicList:
         if count == len(dic):
             dicList.pop()
             count = 0

prettierPrint(dicExample, dicList)

这是根据不同格式进行打印的一个很好的起点，就像op中指定的那样。你真正需要做的只是围绕打印块进行操作。注意，它将查看该值是否为'OrderedDict()'。这取决于你是否使用容器数据类型集合中的东西，你应该做这些故障保护，这样elif块不会因为它的名字而把它视为一个额外的字典。就像现在，一个例子字典

example_dict = {'key1': 'value1',
            'key2': 'value2',
            'key3': {'key3a': 'value3a'},
            'key4': {'key4a': {'key4aa': 'value4aa',
                               'key4ab': 'value4ab',
                               'key4ac': 'value4ac'},
                     'key4b': 'value4b'}

将打印

key3a: value3a
key3a was found in the following path: ['key3']

key2: value2
key2 was found in the following path: []

key1: value1
key1 was found in the following path: []

key4ab: value4ab
key4ab was found in the following path: ['key4', 'key4a']

key4ac: value4ac
key4ac was found in the following path: ['key4', 'key4a']

key4aa: value4aa
key4aa was found in the following path: ['key4', 'key4a']

key4b: value4b
key4b was found in the following path: ['key4']

~修改代码以适应问题的格式~

lastDict = list()
dicList = list()
def prettierPrint(dic, dicList):
    global lastDict
    count = 0
    for key, value in dic.iteritems():
        count+=1
        if str(value) == 'OrderedDict()':
            value = None
        if not isinstance(value, dict):
            if lastDict == dicList:
                sameParents = True
            else:
                sameParents = False

            if dicList and sameParents is not True:
                spacing = ' ' * len(str(dicList))
                print dicList
                print spacing,
                print str(value)

            if dicList and sameParents is True:
                print spacing,
                print str(value)
            lastDict = list(dicList)

        elif isinstance(value, dict):
            dicList.append(key)
            prettierPrint(value, dicList)

        if dicList:
             if count == len(dic):
                 dicList.pop()
                 count = 0

使用相同的示例代码，它将打印以下内容:

['key3']
         value3a
['key4', 'key4a']
                  value4ab
                  value4ac
                  value4aa
['key4']
         value4b

This isn't exactly what is requested in OP. The difference is that a parent^n is still printed, instead of being absent and replaced with white-space. To get to OP's format, you'll need to do something like the following: iteratively compare dicList with the lastDict. You can do this by making a new dictionary and copying dicList's content to it, checking if i in the copied dictionary is the same as i in lastDict, and -- if it is -- writing whitespace to that i position using the string multiplier function.