Python Falcon - Hello World(WSGI)

Quiz

To create a simple Hello World Falcon app, start with importing the library and declaring an instance of App object.

import falcon
app = falcon.App()

Falcon follows REST architectural style. Declare a resource class that includes one or more methods representing the standard HTTP verbs. The following HelloResource class contains on_get() method that is expected to get called when the server receives GET request. The method returns Hello World response.

class HelloResource:
   def on_get(self, req, resp):
   """Handles GET requests"""
   resp.status = falcon.HTTP_200
   resp.content_type = falcon.MEDIA_TEXT
   resp.text = (
      'Hello World'
   )

To invoke this method, we need to register it to a route or URL. The Falcon application object handles the incoming requests by assigning the handler methods to corresponding URLs by add_rule method.

hello = HelloResource()
app.add_route('/hello', hello)

The Falcon application object is nothing but a WSGI application. We can use the built-in WSGI server in the wsgiref module of Python's standard library.

from wsgiref.simple_server import make_server

if __name__ == '__main__':
   with make_server('', 8000, app) as httpd:
   print('Serving on port 8000...')
# Serve until process is killed
httpd.serve_forever()

Example

Let us put all these code fragments in hellofalcon.py

from wsgiref.simple_server import make_server

import falcon

app = falcon.App()

class HelloResource:
   def on_get(self, req, resp):
      """Handles GET requests"""
      resp.status = falcon.HTTP_200
      resp.content_type = falcon.MEDIA_TEXT
      resp.text = (
         'Hello World'
      )
hello = HelloResource()

app.add_route('/hello', hello)

if __name__ == '__main__':
   with make_server('', 8000, app) as httpd:
   print('Serving on port 8000...')
# Serve until process is killed
httpd.serve_forever()

Run this code from the command prompt.

(falconenv) E:\falconenv>python hellofalcon.py
Serving on port 8000...

Output

In another terminal, run the Curl command as follows −

C:\Users\user>curl localhost:8000/hello
Hello World

You can also open a browser window and enter the above URL to obtain the "Hello World" response.

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