import json
data1 = {
 "TestId": "testcase001",
 "Method": "post",
 "Title": "登录测试",
 "Desc": "登录基准测试",
 "Url": "http://xxx.xxx.xxx.xx",
 "InputArg": {
  "username": "王小丫",
  "passwd": "123456",
 },
 "Result": {
  "errorno": "0"
 }
}
with open('casedate.json', 'w', encoding='utf-8') as f:
 json.dump(data1, f, sort_keys=True, indent=4)

{
 "Desc": "",
 "InputArg": {
  "passwd": "123456",
  "username": ""
 },
 "Method": "post",
 "Result": {
  "errorno": "0"
 },
 "TestId": "testcase001",
 "Title": "",
 "Url": "http://xxx.xxx.xxx.xx"
}

{
 "Desc": "\u767b\u5f55\u57fa\u51c6\u6d4b\u8bd5",
 "InputArg": {
  "passwd": "123456",
  "username": "\u738b\u5c0f\u4e2b"
 },
 "Method": "post",
 "Result": {
  "errorno": "0"
 },
 "TestId": "testcase001",
 "Title": "\u767b\u5f55\u6d4b\u8bd5",
 "Url": "http://xxx.xxx.xxx.xx"
}

with open('result.txt', 'a+', encoding='utf-8') as rst:
 rst.write('return data')
 rst.write('|')
 for x in r.items():
  rst.write(x[0])
  rst.write(':')