CODEWITHSUNDEEP
pythonjsonhttpflaskrequest
user1579970
user1579970

Reputation: 379

Why does Flask 'POST' not return a simple JSON object?

I have tried to find similar questions (or documentation) with little success, so I would be very grateful if somebody could point me in the direction of where I have gone wrong here.

In Python 3, I have used Flask to receive HTTP requests for JSON and return them.

from flask import Flask, request
app=Flask(__name__, template_folder='')

@app.route('/json', methods=['POST'])
def json():
    return format(request)

I am using Postman to POST the following to 127.0.0.1/json (to confirm: 127.0.0.1/json works perfectly well if I just ask it to return "Hello World"):

{
    "test":"Hello World"
}

Then Postman responds with:

<Request 'http://127.0.0.1:5000/json' [POST]>

So far, so good. But it reports there is an "Invalid character in attribute name".

Furthermore, when I change the Python script to:

from flask import Flask, request
app=Flask(__name__, template_folder='')

@app.route('/json', methods=['POST'])
def json():
    return format(request.get_json())

The script returns "None" to Postman, despite a JSON object being POST'ed' to it.

Thanks very much to anyone who can clarify this for me. I usually try to debug myself, but this has had me really stumped for a few hours. I am sure I am doing something really stupid! Thanks a lot!

Upvotes: 0

Views: 995

Answers (2)

user1579970
user1579970

Reputation: 379

OK, for whatever reason the JSON object was not being parsed as 'application/json', I fixed this problem:

return format(request.get_json(force=True))

the argument force=True will process the JSON anyhow.

Thank you very much everybody for your help! Hope this helps somebody else who's a bit confused...

Upvotes: 1

turnip
turnip

Reputation: 2346

I suspect you are not sending the payload as JSON from Postman.

It should look like this:

enter image description here

Then when you do request.json in your Flask app you should see the JSON. Note that it is not request.json()

Upvotes: 0

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