json.loads報錯：Expecting property name enclosed in double quotes: line 2 column 3 (char 4)

今天在讀取json文件時報錯：Expecting property name enclosed in double quotes: line 2 column 3 (char 4)

原來是json文件格式錯誤，json文件必須用雙引號！！！

{
  "def_path": "f://"
}