Merge pull request #54 from raj-patra/flask-examples

Add Flask/flask-restful

Author: Bachittarjeet

Flask/flask-restful/app.py

@@ -0,0 +1,64 @@
+"""
+Flask Example - Class Based Flask API using Flask-RESTful
+Level - Intermediate
+Author - [Raj Patra](https:github.com/raj-patra)
+"""
+
+# Importing flask module in the project is mandatory
+# An object of Flask class is our WSGI application.
+from flask import Flask
+
+# Flask-RESTful is an extension for Flask that adds support for quickly building REST APIs.
+from flask_restful import Api, Resource
+from flask_cors import CORS
+from config import Config
+
+# Flask constructor takes the name of current module (__name__) as argument.
+app = Flask(__name__)
+
+# It is always a good practice to load the app configuration from a different file.
+app.config.from_object(Config())
+
+# Enabling CORS allows our API to be used from all hosts.
+cors = CORS(app, resources={r"/*": {"origins": "*"}})
+
+# Passing our flask app to initialize the Api class from flask_restful.
+api = Api(app)
+
+
+"""
+General practice is to assign the index route 
+to atleast one function to avoid 404 error on the
+home route.
+
+‘/’ URL is bound with hello_world() function.
+"""
+@app.route('/', methods=['GET'])
+def index():
+    return "Welcome to Demo-Flask-App", 200
+
+
+# Resource classes should be inherited from the Resource class
+class Greeting(Resource):
+    def __init__(self):
+        # Constructor not necessary for Resource classes.
+        pass
+
+    # All basic HTTP methods already exist in Resource class
+    # We over-write the functions after inheriting the Resource class
+    def get(self, name: str = None):
+        if name:
+            return f"Hello, {name}"
+        else:
+            return 'Please provide a name "/hello/\{name\}"'
+
+    # Similarly other functions such as `post`, `put`, `delete`
+    # can be overwritten according to the project requirements
+
+# Every resource added into `api` becomes an endpoint for flask.
+# Every resources should have a class with basic HTTP methods as its member functions.
+api.add_resource(Greeting, '/hello/<name>')
+
+
+if __name__ == '__main__':
+    app.run(use_reloader=True)

Flask/flask-restful/config.py

@@ -0,0 +1,5 @@
+
+class Config(object):
+    DEBUG = True
+    TESTING = False
+    CORS_HEADERS = 'Content-Type'

Flask/flask-restful/requirements.txt

@@ -0,0 +1,3 @@
+Flask
+Flask-RESTful
+Flask-Cors