Cannot unmarshal a post json python request in Go

Question

Here is my python code (client side) :

import requests
import json
import datetime
headers = {'Content-type': 'application/json',"Authorization":"Bearer MYREALLYLONGTOKENIGOT" }
url = 'http://127.0.0.1:9210/59c94c860a52840958543027/comment/59dea421c26d684270e9321e'
data = { 'sender' : '59c94c860a52840958543027', 'receiver':'59dea421c26d684270e9321e',
        'score' :5,
        'text':'tres jolie 2'}
data_json = json.dumps(data)
r = requests.post(url=url,headers=headers,json=data_json)
r.json()

And here is my golang server side code :

type CommentSent struct {
    Sender    string `json:"sender,omitempty"`
    Receiver  string `json:"receiver,omitempty"`
    Score     int `json:"score,omitempty"`
    Text      string `json:"text,omitempty"`
}


func PostComment(w http.ResponseWriter, r *http.Request) {
    var token string
    token = getToken(r)
    fmt.Println(token)
    vars := mux.Vars(r)
    idUser := vars["idUser"]
    idUserReceiver := vars["idUserReceiver"]
    fmt.Println(idUser)
    fmt.Println(idUserReceiver)
    var commentSend = CommentSend{}
    // body, err := ioutil.ReadAll(r.Body)
    // log.Println(string(body))
    decoder := json.NewDecoder(r.Body)
    err := decoder.Decode(&commentSend)
    if (err != nil){
        Info.Println("error")
        Info.Println(err)

    }

here is what give me the commented lines :

2017/10/12 18:21:29 "{\"sender\": \"59c94c860a52840958543027\", \"score\": 5, \"receiver\": \"59dea421c26d684270e9321e\", \"text\": \"tres jolie 2\"}"

and here is the error that i get :

INFO: 2017/10/12 18:22:32 comment.go:235: json: cannot unmarshal string into Go value of type main.CommentSent

And i don't understand why i have this error the json and python part seems correct and also the golang server side seems also correct.

Answer 1

Your entire request body is a quoted JSON string, rather than raw JSON.

"{\"sender\":....

Either send raw JSON, i.e.:

{"sender":...

Or un-escape it in your Go program. Sending raw JSON is probably the better solution. How to do that, I don't know, as I'm not a Python guru.

Answer 2

I know there is an answer that covers the go side, but when it comes to Python, you shouldn't convert the dictionary to a json. The requests library should do that for you and ensures that the data is sent properly.