如何在Python中漂亮地打印深度为~4的字典?我尝试用pprint()进行漂亮的打印,但它不起作用:

import pprint 
pp = pprint.PrettyPrinter(indent=4)
pp.pprint(mydict)

我只是想要一个缩进(“\t”)为每个嵌套,这样我就会得到这样的东西:

key1
    value1
    value2
    key2
       value1
       value2

等。

我该怎么做呢?


当前回答

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。

其他回答

至于已经做了什么,我没有看到任何漂亮的打印机,至少模仿python解释器的输出非常简单的格式,所以这里是我的:

class Formatter(object):
    def __init__(self):
        self.types = {}
        self.htchar = '\t'
        self.lfchar = '\n'
        self.indent = 0
        self.set_formater(object, self.__class__.format_object)
        self.set_formater(dict, self.__class__.format_dict)
        self.set_formater(list, self.__class__.format_list)
        self.set_formater(tuple, self.__class__.format_tuple)

    def set_formater(self, obj, callback):
        self.types[obj] = callback

    def __call__(self, value, **args):
        for key in args:
            setattr(self, key, args[key])
        formater = self.types[type(value) if type(value) in self.types else object]
        return formater(self, value, self.indent)

    def format_object(self, value, indent):
        return repr(value)

    def format_dict(self, value, indent):
        items = [
            self.lfchar + self.htchar * (indent + 1) + repr(key) + ': ' +
            (self.types[type(value[key]) if type(value[key]) in self.types else object])(self, value[key], indent + 1)
            for key in value
        ]
        return '{%s}' % (','.join(items) + self.lfchar + self.htchar * indent)

    def format_list(self, value, indent):
        items = [
            self.lfchar + self.htchar * (indent + 1) + (self.types[type(item) if type(item) in self.types else object])(self, item, indent + 1)
            for item in value
        ]
        return '[%s]' % (','.join(items) + self.lfchar + self.htchar * indent)

    def format_tuple(self, value, indent):
        items = [
            self.lfchar + self.htchar * (indent + 1) + (self.types[type(item) if type(item) in self.types else object])(self, item, indent + 1)
            for item in value
        ]
        return '(%s)' % (','.join(items) + self.lfchar + self.htchar * indent)

要初始化它:

pretty = Formatter()

它可以支持为已定义的类型添加格式化器,你只需要为它创建一个函数,然后用set_formater将它绑定到你想要的类型:

from collections import OrderedDict

def format_ordereddict(self, value, indent):
    items = [
        self.lfchar + self.htchar * (indent + 1) +
        "(" + repr(key) + ', ' + (self.types[
            type(value[key]) if type(value[key]) in self.types else object
        ])(self, value[key], indent + 1) + ")"
        for key in value
    ]
    return 'OrderedDict([%s])' % (','.join(items) +
           self.lfchar + self.htchar * indent)
pretty.set_formater(OrderedDict, format_ordereddict)

由于历史原因,我保留了之前的漂亮打印机,它是一个函数而不是一个类,但它们都可以以同样的方式使用,类版本只是允许更多:

def pretty(value, htchar='\t', lfchar='\n', indent=0):
    nlch = lfchar + htchar * (indent + 1)
    if type(value) is dict:
        items = [
            nlch + repr(key) + ': ' + pretty(value[key], htchar, lfchar, indent + 1)
            for key in value
        ]
        return '{%s}' % (','.join(items) + lfchar + htchar * indent)
    elif type(value) is list:
        items = [
            nlch + pretty(item, htchar, lfchar, indent + 1)
            for item in value
        ]
        return '[%s]' % (','.join(items) + lfchar + htchar * indent)
    elif type(value) is tuple:
        items = [
            nlch + pretty(item, htchar, lfchar, indent + 1)
            for item in value
        ]
        return '(%s)' % (','.join(items) + lfchar + htchar * indent)
    else:
        return repr(value)

使用它:

>>> a = {'list':['a','b',1,2],'dict':{'a':1,2:'b'},'tuple':('a','b',1,2),'function':pretty,'unicode':u'\xa7',("tuple","key"):"valid"}
>>> a
{'function': <function pretty at 0x7fdf555809b0>, 'tuple': ('a', 'b', 1, 2), 'list': ['a', 'b', 1, 2], 'dict': {'a': 1, 2: 'b'}, 'unicode': u'\xa7', ('tuple', 'key'): 'valid'}
>>> print(pretty(a))
{
    'function': <function pretty at 0x7fdf555809b0>,
    'tuple': (
        'a',
        'b',
        1,
        2
    ),
    'list': [
        'a',
        'b',
        1,
        2
    ],
    'dict': {
        'a': 1,
        2: 'b'
    },
    'unicode': u'\xa7',
    ('tuple', 'key'): 'valid'
}

相对于其他版本:

This solution looks directly for object type, so you can pretty print almost everything, not only list or dict. Doesn't have any dependancy. Everything is put inside a string, so you can do whatever you want with it. The class and the function has been tested and works with Python 2.7 and 3.4. You can have all type of objects inside, this is their representations and not theirs contents that being put in the result (so string have quotes, Unicode string are fully represented ...). With the class version, you can add formatting for every object type you want or change them for already defined ones. key can be of any valid type. Indent and Newline character can be changed for everything we'd like. Dict, List and Tuples are pretty printed.

某物,我觉得很漂亮

def pretty(d, indent=0):
    for key, value in d.iteritems():
        if isinstance(value, dict):
            print '\t' * indent + (("%30s: {\n") % str(key).upper())
            pretty(value, indent+1)
            print '\t' * indent + ' ' * 32 + ('} # end of %s #\n' % str(key).upper())
        elif isinstance(value, list):
            for val in value:
                print '\t' * indent + (("%30s: [\n") % str(key).upper())
                pretty(val, indent+1)
                print '\t' * indent + ' ' * 32 + ('] # end of %s #\n' % str(key).upper())
        else:
            print '\t' * indent + (("%30s: %s") % (str(key).upper(),str(value)))

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.

我的第一个想法是JSON序列化器可能很擅长嵌套字典,所以我会欺骗并使用它:

>>> import json
>>> print(json.dumps({'a':2, 'b':{'x':3, 'y':{'t1': 4, 't2':5}}},
...                  sort_keys=True, indent=4))
{
    "a": 2,
    "b": {
        "x": 3,
        "y": {
            "t1": 4,
            "t2": 5
        }
    }
}

使用这个函数:

def pretty_dict(d, n=1):
    for k in d:
        print(" "*n + k)
        try:
            pretty_dict(d[k], n=n+4)
        except TypeError:
            continue

这样叫它:

pretty_dict(mydict)