JSON

字典转字符串 json.dumps

import json
data = {
    'name':'wonvy',
    'day':'2020',
    'place':'xiamen'
}
print(type(data)) #返回类型
json_str = json.dumps(data) #字典 转 字符串
print(type(json_str))
print(json_str)

默认无序字典

import operator
x = {"c": "1", "b": 2, "a": 3}
sorted_x = sorted(x.items(), key=operator.itemgetter(0))
print(sorted_x)

有序字典

from collections import OrderedDict
x = OrderedDict() #需要初始化
x["c"] = 3
x["b"] = 2
x["a"] = 1
print(x)

一键多值字典

from collections import defaultdict
x = defaultdict(list)
x["color"].append("red")
x["color"].append("blue")
x["name"].append("li")
x["name"].append("wang")
print(type(x))
print(x)

写入指定数据