Can't send POST request to my basic FLASK Python application

Question

I am trying to test the basic HTTP requests in my simple rest api using Flask framework in Python. The GET method worked just fine not the POST method yet. here is the route:

@app.route('/lang', methods=['POST'])
def addOne():
    language = {'name' : request.json['name']}
    languages.append(language)
    return jsonify({'languages' : languages})

My languages dictionary:

languages = [{'name' : 'JavaScript'},{'name' : 'Java'}, {'name' : 'Python'}]

I am trying to use Postman application to post a new language to the dictionary, here is the request:

http://127.0.0.1:8080/lang

And in the body, row I placed this:

{"name" : "C++"}

It gives me this error:

  File "/home/pi/IoT_api/restful.py", line 22, in addOne
    language = {'name' : request.json['name']}
TypeError: 'NoneType' object has no attribute '__getitem__'

Did you tell postman to send a JSON content type header? – Daniel Roseman Jul 24 '17 at 22:28 — Daniel Roseman, Jul 24 '17 at 22:28
What headers are you sending? – Jim Wright Jul 24 '17 at 22:51 — Jim Wright, Jul 24 '17 at 22:51
Content-Type: application/json? – Jim Wright Jul 24 '17 at 23:12 — Jim Wright, Jul 24 '17 at 23:12

score 1 · Answer 1 · answered Jul 25 '17 at 10:24

1

The documentation clearly says:

If the mimetype is application/json this will contain the parsed JSON data. Otherwise this will be None.

So make sure to correctly define the 'Content-Type' header with Postman

answered Jul 25 '17 at 10:24

lee-pai-long

2,147
17
18

score 0 · Answer 2 · answered Oct 20 '18 at 11:46

0

with the new flask version, change how you get post data from

language = {'name' : request.json['name']}

to

language = request.get_json('name')

answered Oct 20 '18 at 11:46

felix rono

1
1

Can't send POST request to my basic FLASK Python application

2 Answers2