python json序列化预处理

背景

python内置库json序列化支持的数据类型不多，经常在使用dumps函数时遇到对象不支持序列化的情况，在json库的encoder.py文件中有如下说明

	Extensible JSON <http://json.org> encoder for Python data structures.
    Supports the following objects and types by default:
    +-------------------+---------------+
    | Python            | JSON          |
    +===================+===============+
    | dict              | object        |
    +-------------------+---------------+
    | list, tuple       | array         |
    +-------------------+---------------+
    | str               | string        |
    +-------------------+---------------+
    | int, float        | number        |
    +-------------------+---------------+
    | True              | true          |
    +-------------------+---------------+
    | False             | false         |
    +-------------------+---------------+
    | None              | null          |
    +-------------------+---------------+
    To extend this to recognize other objects, subclass and implement a
    ``.default()`` method with another method that returns a serializable
    object for ``o`` if possible, otherwise it should call the superclass
    implementation (to raise ``TypeError``).

解决方案

在使用内置json序列化函数前，可以预处理序列化对象

import json

def jsonPrepare(data, encoding='utf8'):
    # 不处理
    if data is None or data is True or data is False:
        return data
    if isinstance(data, int) or isinstance(data, float) or isinstance(data, str):
        return data
    # 遍历处理
    if isinstance(data, list) or isinstance(data, set) or isinstance(data, tuple):
        return list([jsonPrepare(i, encoding=encoding) for i in data])
    elif isinstance(data, dict):
        return {
    
    jsonPrepare(k, encoding=encoding): jsonPrepare(v, encoding=encoding) for k, v in data.items()}
    # 解码
    elif isinstance(data, bytes):
        return data.decode(encoding=encoding)
    else:
        return str(data)

data = json.dumps(jsonPrepare(data))