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

下面是我根据sth的注释写的函数。它的工作原理与json相同。转储与缩进,但我使用制表符而不是缩进的空间。在Python 3.2+中,您可以直接将缩进指定为'\t',但在2.7中不能。

def pretty_dict(d):
    def pretty(d, indent):
        for i, (key, value) in enumerate(d.iteritems()):
            if isinstance(value, dict):
                print '{0}"{1}": {{'.format( '\t' * indent, str(key))
                pretty(value, indent+1)
                if i == len(d)-1:
                    print '{0}}}'.format( '\t' * indent)
                else:
                    print '{0}}},'.format( '\t' * indent)
            else:
                if i == len(d)-1:
                    print '{0}"{1}": "{2}"'.format( '\t' * indent, str(key), value)
                else:
                    print '{0}"{1}": "{2}",'.format( '\t' * indent, str(key), value)
    print '{'
    pretty(d,indent=1)
    print '}'

Ex:

>>> dict_var = {'a':2, 'b':{'x':3, 'y':{'t1': 4, 't2':5}}}
>>> pretty_dict(dict_var)
{
    "a": "2",
    "b": {
        "y": {
            "t2": "5",
            "t1": "4"
        },
        "x": "3"
    }
}

其他回答

我只是在得到某事物的答案并做了一个很小但非常有用的修改之后回到这个问题。该函数打印JSON树中的所有键以及该树中叶节点的大小。

def print_JSON_tree(d, indent=0):
    for key, value in d.iteritems():
        print '    ' * indent + unicode(key),
        if isinstance(value, dict):
            print; print_JSON_tree(value, indent+1)
        else:
            print ":", str(type(d[key])).split("'")[1], "-", str(len(unicode(d[key])))

当您有大型JSON对象并想要找出肉在哪里时,这非常好。例子:

>>> print_JSON_tree(JSON_object)
key1
    value1 : int - 5
    value2 : str - 16
    key2
       value1 : str - 34
       value2 : list - 5623456

这将告诉您,您所关心的大部分数据可能在JSON_object['key1']['key2']['value2']中,因为该值格式化为字符串的长度非常大。

我把sth的答案稍微修改一下,以适应我的嵌套字典和列表的需要:

def pretty(d, indent=0):
    if isinstance(d, dict):
        for key, value in d.iteritems():
            print '\t' * indent + str(key)
            if isinstance(value, dict) or isinstance(value, list):
                pretty(value, indent+1)
            else:
                print '\t' * (indent+1) + str(value)
    elif isinstance(d, list):
        for item in d:
            if isinstance(item, dict) or isinstance(item, list):
                pretty(item, indent+1)
            else:
                print '\t' * (indent+1) + str(item)
    else:
        pass

然后输出如下:

>>> 
xs:schema
    @xmlns:xs
        http://www.w3.org/2001/XMLSchema
    xs:redefine
        @schemaLocation
            base.xsd
        xs:complexType
            @name
                Extension
            xs:complexContent
                xs:restriction
                    @base
                        Extension
                    xs:sequence
                        xs:element
                            @name
                                Policy
                            @minOccurs
                                1
                            xs:complexType
                                xs:sequence
                                    xs:element
                                            ...

最简单的方法是安装IPython并使用如下所示的方法

from IPython.lib.pretty import pretty


class MyClass:
    __repr__(self):
       return pretty(data)  # replace data with what makes sense

在你的情况下

print(pretty(mydict))

prettyformatter

免责声明:我是该软件包的作者。

有关与其他格式化程序的比较,请参阅其他格式化程序。


格式化

不像pprint。Pprint, prettyformatter更多地垂直传播,并尝试更多地对齐项目。

与json。转储,prettyformatter通常更紧凑,并尝试在合理的地方对齐字典值。

from prettyformatter import pprint

batters = [
    {"id": "1001", "type": "Regular"},
    {"id": "1002", "type": "Chocolate"},
    {"id": "1003", "type": "Blueberry"},
    {"id": "1004", "type": "Devil's Food"},
]

toppings = [
    {"id": "5001", "type": None},
    {"id": "5002", "type": "Glazed"},
    {"id": "5005", "type": "Sugar"},
    {"id": "5007", "type": "Powdered Sugar"},
    {"id": "5006", "type": "Chocolate with Sprinkles"},
    {"id": "5003", "type": "Chocolate"},
    {"id": "5004", "type": "Maple"},
]

data = {"id": "0001", "type": "donut", "name": "Cake", "ppu": 0.55, "batters": batters, "topping": toppings}

pprint(data)

输出:

{
    "id"    : "0001",
    "type"  : "donut",
    "name"  : "Cake",
    "ppu"   : 0.55,
    "batters":
        [
            {"id": "1001", "type": "Regular"},
            {"id": "1002", "type": "Chocolate"},
            {"id": "1003", "type": "Blueberry"},
            {"id": "1004", "type": "Devil's Food"},
        ],
    "topping":
        [
            {"id": "5001", "type": None},
            {"id": "5002", "type": "Glazed"},
            {"id": "5005", "type": "Sugar"},
            {"id": "5007", "type": "Powdered Sugar"},
            {"id": "5006", "type": "Chocolate with Sprinkles"},
            {"id": "5003", "type": "Chocolate"},
            {"id": "5004", "type": "Maple"},
        ],
}

特性

请在这里查看完整的文档。

JSON

不像pprint。pprint, prettyformatter通过JSON =True参数支持JSON转换。这包括将None更改为null, True更改为True, False更改为False,以及正确使用引号。

与json。转储,prettyformatter支持更多数据类型的JSON强制。这包括将任何数据类或映射更改为字典,将任何可迭代对象更改为列表。

from dataclasses import dataclass

from prettyformatter import PrettyDataclass, pprint


@dataclass(unsafe_hash=True)
class Point(PrettyDataclass):
    x: int
    y: int


pprint((Point(1, 2), Point(3, 4)), json=True)

输出:

[{"x": 1, "y": 2}, {"x": 3, "y": 4}]

定制

不像pprint。Pprint或json。转储,prettyformatter支持轻松定制附加类型。

为一个prettyformatter实现__pargs__和/或__pkwargs__方法。PrettyClass子类允许用户以“cls_name(*args, **kwargs)”的形式轻松地自定义类。

from prettyformatter import PrettyClass


class Dog(PrettyClass):

    def __init__(self, name, **kwargs):
        self.name = name

    def __pkwargs__(self):
        return {"name": self.name}


print(Dog("Fido"))
"""
Dog(name="Fido")
"""

print(Dog("Fido"), json=True)
"""
{"name": "Fido"}
"""

实现__pformat__方法可以实现更具体的pformat函数。

实现@prettyformatter。Register函数还允许以与实现__pformat__相同的方式自定义已经存在的类。

import numpy as np
from prettyformatter import pprint, register

@register(np.ndarray)
def pformat_ndarray(obj, specifier, depth, indent, shorten, json):
    if json:
        return pformat(obj.tolist(), specifier, depth, indent, shorten, json)
    with np.printoptions(formatter=dict(all=lambda x: format(x, specifier))):
        return repr(obj).replace("\n", "\n" + " " * depth)

pprint(dict.fromkeys("ABC", np.arange(9).reshape(3, 3)))

输出:

{
    "A":
        array([[0, 1, 2],
               [3, 4, 5],
               [6, 7, 8]]),
    "B":
        array([[0, 1, 2],
               [3, 4, 5],
               [6, 7, 8]]),
    "C":
        array([[0, 1, 2],
               [3, 4, 5],
               [6, 7, 8]]),
}

从这个链接:

def prnDict(aDict, br='\n', html=0,
            keyAlign='l',   sortKey=0,
            keyPrefix='',   keySuffix='',
            valuePrefix='', valueSuffix='',
            leftMargin=0,   indent=1 ):
    '''
return a string representive of aDict in the following format:
    {
     key1: value1,
     key2: value2,
     ...
     }

Spaces will be added to the keys to make them have same width.

sortKey: set to 1 if want keys sorted;
keyAlign: either 'l' or 'r', for left, right align, respectively.
keyPrefix, keySuffix, valuePrefix, valueSuffix: The prefix and
   suffix to wrap the keys or values. Good for formatting them
   for html document(for example, keyPrefix='<b>', keySuffix='</b>'). 
   Note: The keys will be padded with spaces to have them
         equally-wide. The pre- and suffix will be added OUTSIDE
         the entire width.
html: if set to 1, all spaces will be replaced with '&nbsp;', and
      the entire output will be wrapped with '<code>' and '</code>'.
br: determine the carriage return. If html, it is suggested to set
    br to '<br>'. If you want the html source code eazy to read,
    set br to '<br>\n'

version: 04b52
author : Runsun Pan
require: odict() # an ordered dict, if you want the keys sorted.
         Dave Benjamin 
         http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/161403
    '''

    if aDict:

        #------------------------------ sort key
        if sortKey:
            dic = aDict.copy()
            keys = dic.keys()
            keys.sort()
            aDict = odict()
            for k in keys:
                aDict[k] = dic[k]

        #------------------- wrap keys with ' ' (quotes) if str
        tmp = ['{']
        ks = [type(x)==str and "'%s'"%x or x for x in aDict.keys()]

        #------------------- wrap values with ' ' (quotes) if str
        vs = [type(x)==str and "'%s'"%x or x for x in aDict.values()] 

        maxKeyLen = max([len(str(x)) for x in ks])

        for i in range(len(ks)):

            #-------------------------- Adjust key width
            k = {1            : str(ks[i]).ljust(maxKeyLen),
                 keyAlign=='r': str(ks[i]).rjust(maxKeyLen) }[1]

            v = vs[i]        
            tmp.append(' '* indent+ '%s%s%s:%s%s%s,' %(
                        keyPrefix, k, keySuffix,
                        valuePrefix,v,valueSuffix))

        tmp[-1] = tmp[-1][:-1] # remove the ',' in the last item
        tmp.append('}')

        if leftMargin:
          tmp = [ ' '*leftMargin + x for x in tmp ]

        if html:
            return '<code>%s</code>' %br.join(tmp).replace(' ','&nbsp;')
        else:
            return br.join(tmp)     
    else:
        return '{}'

'''
Example:

>>> a={'C': 2, 'B': 1, 'E': 4, (3, 5): 0}

>>> print prnDict(a)
{
 'C'   :2,
 'B'   :1,
 'E'   :4,
 (3, 5):0
}

>>> print prnDict(a, sortKey=1)
{
 'B'   :1,
 'C'   :2,
 'E'   :4,
 (3, 5):0
}

>>> print prnDict(a, keyPrefix="<b>", keySuffix="</b>")
{
 <b>'C'   </b>:2,
 <b>'B'   </b>:1,
 <b>'E'   </b>:4,
 <b>(3, 5)</b>:0
}

>>> print prnDict(a, html=1)
<code>{
&nbsp;'C'&nbsp;&nbsp;&nbsp;:2,
&nbsp;'B'&nbsp;&nbsp;&nbsp;:1,
&nbsp;'E'&nbsp;&nbsp;&nbsp;:4,
&nbsp;(3,&nbsp;5):0
}</code>

>>> b={'car': [6, 6, 12], 'about': [15, 9, 6], 'bookKeeper': [9, 9, 15]}

>>> print prnDict(b, sortKey=1)
{
 'about'     :[15, 9, 6],
 'bookKeeper':[9, 9, 15],
 'car'       :[6, 6, 12]
}

>>> print prnDict(b, keyAlign="r")
{
        'car':[6, 6, 12],
      'about':[15, 9, 6],
 'bookKeeper':[9, 9, 15]
}
'''