Python Flask Restful API

Question

Part of my Flask code:

@app.route('/api/post', methods=['POST']) 
def post():
    body = request.get_json()
    json_body = json.loads(body)
    new_id = mongo.db.Projects.insert(json_body)
    return str(new_id)

Script to post a new database entry:

payload =  { 'ProjectName' : 'KdB Test Project' }
headers = {'Content-type': 'application/json', 'Accept': 'application/json'}
r = requests.post('http://localhost:5000/api/post', headers=headers, data=json.dumps(payload))

I keep getting json decoder TypeError problems, eg

TypeError: expected string or buffer
2016-08-16 15:19:31,388 - werkzeug - INFO - 127.0.0.1 - - [16/Aug/2016 15:19:31] "POST /api/post HTTP/1.1" 500 -

I have tried several things, incl. posting strings. Any clue what is wrong with the way I post a dictionary? The problem appears to be at the point of body = request.get_json(). I don't think I am picking up any data...

Answer 1

You don't need to loads request message to get dict format. Information stored in body variable is already in dict form. Simply doing the following should remove the error:

@app.route('/api/post', methods=['POST']) 
def post():
    body = request.get_json()
    # json_body = json.loads(body)
    new_id = mongo.db.Projects.insert( body )
    return str( new_id )

Answer 2

http://flask.pocoo.org/docs/0.11/api/#flask.Request.get_json

get_json is probably returning a dict already, so you don't need to call json.loads(body) (this is what most likely causes the TypeError ).

@app.route('/api/post', methods=['POST']) 
def post():
    json_body = request.get_json()
    new_id = mongo.db.Projects.insert(json_body)
    return str(new_id)