python 報錯TypeError: can only concatenate str (not "bytes") to str

背景：項目Python2.7升級到Python3.8,Django1.10升級到Django3.0

因爲python3.4後不能直接使用unicode(value, 'utf-8')了

所以代碼

data = '{"id":"' + location_key_id + '","location_name": "' + unicode(location_name, 'utf-8') + '","leaf:"'+true+'"}'

需要刪除，可以直接變成：

data = '{"id":"' + location_key_id + '","location_name": "' + location_name + '","leaf:"'+true+'"}'

但是調用代碼是報錯

can only concatenate str (not "bytes") to str

修改成：

data = '{"id":"' + location_key_id + '","location_name": "' + str(location_name) + '","leaf:"'+true+'"}'

問題解決！！！