Python JSON 基本操作

Python version ： 3.4.4

测试数据：

import jsonaa = {"name": "kk", "age": 99 }bb = [ {"name": "mm", "age": 10},{"name": "QQ", "age": 20},{"name": "hh", "age": 50} ]json模块提供的函数 json.dumps() 和 json.loads()
输出：
>>> PRint(bb)[{'name': 'mm', 'age': 10}, {'name': 'qq', 'age': 20}, {'name': 'hh', 'age': 50}]>>>>>> data=json.dumps(bb)>>> print(data)[{"name": "mm", "age": 10}, {"name": "qq", "age": 20}, {"name": "hh", "age": 50}]>>>>>> load = json.loads(data)>>> print(load)[{'name': 'mm', 'age': 10}, {'name': 'qq', 'age': 20}, {'name': 'hh', 'age': 50}]>>>排序：
>>> data = json.dumps(bb,sort_keys=True)>>> print(data)[{"age": 10, "name": "mm"}, {"age": 20, "name": "qq"}, {"age": 50, "name": "hh"}]>>>格式化输出：
>>> data = json.dumps(bb,indent=4)>>> print(data)[    {        "name": "mm",        "age": 10    },    {        "name": "qq",        "age": 20    },    {        "name": "hh",        "age": 50    }]>>>输出某行数据：
>>> print(bb[0]){'name': 'mm', 'age': 10}>>>>>> print(bb[1]){'name': 'qq', 'age': 20}>>>>>> print(bb[2]){'name': 'hh', 'age': 50}>>>输出某行数据某个值：
>>> print(bb[1]["name"])qq>>>>>> print(bb[1]["age"])20>>>
遍历/循环 JSON ：
>>> bb = [ {"name": "mm", "age": 10},{"name": "qq", "age": 20},{"name": "hh", "age": 50} ]>>>>>> for item in bb:...     print(item,item["name"])...{'name': 'mm', 'age': 10} mm{'name': 'qq', 'age': 20} qq{'name': 'hh', 'age': 50} hh>>>>>> for i in range(len(bb)):...     print(i,bb[i],bb[i]["name"])...0 {'name': 'mm', 'age': 10} mm1 {'name': 'qq', 'age': 20} qq2 {'name': 'hh', 'age': 50} hh>>>>>> for i,item in enumerate(bb):...     print(i,item,item["name"])...0 {'name': 'mm', 'age': 10} mm1 {'name': 'qq', 'age': 20} qq2 {'name': 'hh', 'age': 50} hh>>>>>> for item in bb:...     print("name=%s,age=%s,age=%f"%(item["name"],item["age"],item["age"]))...name=mm,age=10,age=10.000000name=qq,age=20,age=20.000000name=hh,age=50,age=50.000000>>>>>> for item in bb:...     print("My name is {0} ".format(item["name"]))...My name is mmMy name is qqMy name is hh>>>>>> for i,j in bb:...     print("name: {0}, age: {1}".format(i,j))...name: name, age: agename: name, age: agename: name, age: age>>>json 转 python 数据格式定义:
+---------------+-------------------+| JSON          | Python            |+===============+===================+| object        | dict              |+---------------+-------------------+| array         | list              |+---------------+-------------------+| string        | str               |+---------------+-------------------+| number (int)  | int               |+---------------+-------------------+| number (real) | float             |+---------------+-------------------+| true          | True              |+---------------+-------------------+| false         | False             |+---------------+-------------------+| null          | None              |+---------------+-------------------+python 转 json 数据格式定义:
 +-------------------+---------------+ | Python            | JSON          | +===================+===============+ | dict              | object        | +-------------------+---------------+ | list, tuple       | array         | +-------------------+---------------+ | str               | string        | +-------------------+---------------+ | int, float        | number        | +-------------------+---------------+ | True              | true          | +-------------------+---------------+ | False             | false         | +-------------------+---------------+ | None              | null          | +-------------------+---------------+更多参考：JSON encoder and decoder
 help("json")