Javascript - No 'Access-Control-Allow-Origin' header is present on the requested resource

Question

I need to send data through XmlHttpRequest from JavaScript to Python server. Because I\'m using localhost, I need to use CORS. I\'m using the Flask framework an

Answer 1

When using python 2.7

app = Flask(__name__)
api = Api(app)

@app.after_request
def after_request(response):
  response.headers.add('Access-Control-Allow-Origin', '*')
  response.headers.add('Access-Control-Allow-Headers', 'Content-Type,Authorization')
  response.headers.add('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS')
  return response


if __name__ == '__main__':
    app.run()

When running on python3 or ahead, install flask-cors using the command pip install flask-cors The add the following:

from flask_cors import CORS
app = Flask(__name__)
CORS(app)