Python内置模块：json

json (JavaScript Object Notation) 是一种轻量级的数据交换格式。

>>> import json
>>> json.__file__
'C:\\Python27\\lib\\json\\__init__.pyc'
>>> type(json)
<type 'module'>
>>> dir(json)
['JSONDecoder', 'JSONEncoder', '__all__', '__author__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '__path__', '__version__', '_default_decoder', '_default_encoder', 'decoder', 'dump', 'dumps', 'encoder', 'load', 'loads', 'scanner']
>>>

• json.dump 字典转文件
• json.dumps 字典转字符串
• json.load 文件转字典
• json.loads 字符串转字典

import json

data = {
    "name": "Andy",
    "age": 29,
    "weight": 55.5
}

jsonStr = json.dumps(data)

jsonData = json.loads(jsonStr)

# Writing JSON data
with open("data.json", "w") as f:
    json.dump(data, f)

# indent用法
with open("data.json", "w") as f:
    json.dump(data, f, indent=4)

with open("data.json", "r") as f:
    data = json.load(f)