python通过json读写序列类型的数据文件

import json
class a:
    def writeReadJson(self):
        list2 =['1',5.,7,'3']
        with open("test.txt",'w') as f:
            json.dump(list2,f)#将列表写入f文件
        with open("test.txt", 'r') as f1:
            j = json.load(f1)#将f1文件内容加载并赋给j
        print(j)  #输出{'3': 6, '5': 8}
        print(json.dumps(list2))#输出["1", 5.0, 7, "3"]
a().writeReadJson()