从Python烧瓶API返回Blank

Question

I have an API that must return just blank and status as 200 OK in case there is no data available

I have tried following things and facing these error

if df.empty:
   return '' , 200

This returns "" in the browser

if df.empty:
   return json.loads('{}'), 200

This return {} in the browser

Send status as 204 (NO CONTENT) makes the previous content to be as it is on the browser

How can i return complete blank with status as 200?

Answer 1

I have found solution after thoroughly exploring Flask documents

from flask import Response
.....
if df.empty:
   return Response(status = 200)

Answer 2

Your first example shows in my console, as others have mention in comments:

127.0.0.1 - - [05/Dec/2018 18:46:35] "GET / HTTP/1.1" 200 -

You can also see status of a document in a Network tab in Developers console.

I didn't see 204 - NO CONTENT until I explicitly defined it:

@app.route('/')
def index():
    return '', 204

Your second example didn't work for me and gave me an error:

TypeError: 'dict' object is not callable

EDIT:

This is source of a page in opera (and chrome also).

And this is code for your second example, that I get an error from.

from flask import Flask, json

app = Flask(__name__)


@app.route('/')
def index():
    return json.loads('{}'), 200