我习惯使用CSV文件在Python中输入和输出数据,但这存在明显的挑战。是否有简单的方法将字典(或字典集)存储在JSON或pickle文件中?

例如:

data = {}
data ['key1'] = "keyinfo"
data ['key2'] = "keyinfo2"

我想知道如何保存这个,然后如何加载它回来。


当前回答

为了完整起见,我们应该包括ConfigParser和ConfigParser,它们分别是Python 2和3中的标准库的一部分。这个模块读取和写入一个config/ini文件,并且(至少在Python 3中)在很多方面都像一个字典。它还有一个额外的好处,你可以将多个字典存储到config/ini文件的单独部分中,并收回它们。甜蜜的!

Python 2.7。x的例子。

import ConfigParser

config = ConfigParser.ConfigParser()

dict1 = {'key1':'keyinfo', 'key2':'keyinfo2'}
dict2 = {'k1':'hot', 'k2':'cross', 'k3':'buns'}
dict3 = {'x':1, 'y':2, 'z':3}

# Make each dictionary a separate section in the configuration
config.add_section('dict1')
for key in dict1.keys():
    config.set('dict1', key, dict1[key])
   
config.add_section('dict2')
for key in dict2.keys():
    config.set('dict2', key, dict2[key])

config.add_section('dict3')
for key in dict3.keys():
    config.set('dict3', key, dict3[key])

# Save the configuration to a file
f = open('config.ini', 'w')
config.write(f)
f.close()

# Read the configuration from a file
config2 = ConfigParser.ConfigParser()
config2.read('config.ini')

dictA = {}
for item in config2.items('dict1'):
    dictA[item[0]] = item[1]

dictB = {}
for item in config2.items('dict2'):
    dictB[item[0]] = item[1]

dictC = {}
for item in config2.items('dict3'):
    dictC[item[0]] = item[1]

print(dictA)
print(dictB)
print(dictC)

Python 3。X的例子。

import configparser

config = configparser.ConfigParser()

dict1 = {'key1':'keyinfo', 'key2':'keyinfo2'}
dict2 = {'k1':'hot', 'k2':'cross', 'k3':'buns'}
dict3 = {'x':1, 'y':2, 'z':3}

# Make each dictionary a separate section in the configuration
config['dict1'] = dict1
config['dict2'] = dict2
config['dict3'] = dict3

# Save the configuration to a file
f = open('config.ini', 'w')
config.write(f)
f.close()

# Read the configuration from a file
config2 = configparser.ConfigParser()
config2.read('config.ini')

# ConfigParser objects are a lot like dictionaries, but if you really
# want a dictionary you can ask it to convert a section to a dictionary
dictA = dict(config2['dict1'] )
dictB = dict(config2['dict2'] )
dictC = dict(config2['dict3'])

print(dictA)
print(dictB)
print(dictC)

控制台输出

{'key2': 'keyinfo2', 'key1': 'keyinfo'}
{'k1': 'hot', 'k2': 'cross', 'k3': 'buns'}
{'z': '3', 'y': '2', 'x': '1'}

config.ini的内容

[dict1]
key2 = keyinfo2
key1 = keyinfo

[dict2]
k1 = hot
k2 = cross
k3 = buns

[dict3]
z = 3
y = 2
x = 1

其他回答

如果保存为JSON文件,最好和最简单的方法是:

import json
with open("file.json", "wb") as f:
    f.write(json.dumps(dict).encode("utf-8"))

泡菜保存:

try:
    import cPickle as pickle
except ImportError:  # Python 3.x
    import pickle

with open('data.p', 'wb') as fp:
    pickle.dump(data, fp, protocol=pickle.HIGHEST_PROTOCOL)

有关协议参数的其他信息,请参阅pickle模块文档。

泡菜负载:

with open('data.p', 'rb') as fp:
    data = pickle.load(fp)

JSON保存:

import json

with open('data.json', 'w') as fp:
    json.dump(data, fp)

提供额外的参数,如sort_keys或indent,以获得漂亮的结果。参数sort_keys将按字母顺序对键进行排序,indent将使用indent=N个空格对数据结构进行缩进。

json.dump(data, fp, sort_keys=True, indent=4)

JSON负载:

with open('data.json', 'r') as fp:
    data = json.load(fp)

较短的代码

保存和加载所有类型的python变量(包括字典),每个变量只需一行代码。

data = {'key1': 'keyinfo', 'key2': 'keyinfo2'}

保存:

pickle.dump(data, open('path/to/file/data.pickle', 'wb'))
   

加载:

data_loaded = pickle.load(open('path/to/file/data.pickle', 'rb'))

也许这很明显,但在我试图使它更短之前,我在顶部的答案中使用了两行解。

如果您正在序列化,但在其他程序中不需要数据,我强烈推荐使用shelve模块。可以把它看作一个持久化字典。

myData = shelve.open('/path/to/file')

# Check for values.
keyVar in myData

# Set values
myData[anotherKey] = someValue

# Save the data for future use.
myData.close()

为了完整起见,我们应该包括ConfigParser和ConfigParser,它们分别是Python 2和3中的标准库的一部分。这个模块读取和写入一个config/ini文件,并且(至少在Python 3中)在很多方面都像一个字典。它还有一个额外的好处,你可以将多个字典存储到config/ini文件的单独部分中,并收回它们。甜蜜的!

Python 2.7。x的例子。

import ConfigParser

config = ConfigParser.ConfigParser()

dict1 = {'key1':'keyinfo', 'key2':'keyinfo2'}
dict2 = {'k1':'hot', 'k2':'cross', 'k3':'buns'}
dict3 = {'x':1, 'y':2, 'z':3}

# Make each dictionary a separate section in the configuration
config.add_section('dict1')
for key in dict1.keys():
    config.set('dict1', key, dict1[key])
   
config.add_section('dict2')
for key in dict2.keys():
    config.set('dict2', key, dict2[key])

config.add_section('dict3')
for key in dict3.keys():
    config.set('dict3', key, dict3[key])

# Save the configuration to a file
f = open('config.ini', 'w')
config.write(f)
f.close()

# Read the configuration from a file
config2 = ConfigParser.ConfigParser()
config2.read('config.ini')

dictA = {}
for item in config2.items('dict1'):
    dictA[item[0]] = item[1]

dictB = {}
for item in config2.items('dict2'):
    dictB[item[0]] = item[1]

dictC = {}
for item in config2.items('dict3'):
    dictC[item[0]] = item[1]

print(dictA)
print(dictB)
print(dictC)

Python 3。X的例子。

import configparser

config = configparser.ConfigParser()

dict1 = {'key1':'keyinfo', 'key2':'keyinfo2'}
dict2 = {'k1':'hot', 'k2':'cross', 'k3':'buns'}
dict3 = {'x':1, 'y':2, 'z':3}

# Make each dictionary a separate section in the configuration
config['dict1'] = dict1
config['dict2'] = dict2
config['dict3'] = dict3

# Save the configuration to a file
f = open('config.ini', 'w')
config.write(f)
f.close()

# Read the configuration from a file
config2 = configparser.ConfigParser()
config2.read('config.ini')

# ConfigParser objects are a lot like dictionaries, but if you really
# want a dictionary you can ask it to convert a section to a dictionary
dictA = dict(config2['dict1'] )
dictB = dict(config2['dict2'] )
dictC = dict(config2['dict3'])

print(dictA)
print(dictB)
print(dictC)

控制台输出

{'key2': 'keyinfo2', 'key1': 'keyinfo'}
{'k1': 'hot', 'k2': 'cross', 'k3': 'buns'}
{'z': '3', 'y': '2', 'x': '1'}

config.ini的内容

[dict1]
key2 = keyinfo2
key1 = keyinfo

[dict2]
k1 = hot
k2 = cross
k3 = buns

[dict3]
z = 3
y = 2
x = 1