Python REST-API Development with Flask

Requirements

To install and run these examples you need:

• Python 3.3+
• python3-venv or python3-virtualenv
• git (only to clone this repository)
• docker and docker-compose ( if needed a dockerized flask app )

Installation

The commands below set everything up to run the examples:

$ git clone https://github.com/mamirpanah/flask-restapi.git
$ cd flask-restapi
$ python3 -m venv venv
$ . venv/bin/activate
(venv) pip install -r requirements.txt
$ flask run -h 0.0.0.0 -p 5000

finished

Installation with docker

$ docker build -t python_flask:1 .
$ docker run --rm -it -p 8080:5000 python_flask:1 flask run -h 0.0.0.0 -p 5000

Installation with docker-compose

$ docker-compose up -d --build

note: You can replace "command" of docker-compose.yml with following commands to run flask web server:

• flask run -h 0.0.0.0 -p 5000
• gunicorn -w 2 -b 0.0.0.0:5000 restapi.app:create_app
• python3 -m flask run -h 0.0.0.0 -p 5000

For production use:

note: Never expose the dev server to the outside (such as binding to 0.0.0.0). Use a production WSGI server such as uWSGI or Gunicorn.

$ gunicorn -w 2 -b 0.0.0.0:5005 restapi.app:create_app

Using factory method to import flask web server as an object into another python project:

$ import restapi
$ app_object = restapi.create_app()
$ app_object.run(host="0.0.0.0", port=5005)

How to customize python flask web server as a restful-api:

Creating a REST API for GET request on http://localhost:5000/users

All the things that you should change is in restapi/resource :

1. git clone https://github.com/mamirpanah/flask-restapi.git
2. cd flask-restapi/restapi/resource/apiv1
3. vim init.py
4. vim user.py

Step 3 in detail:

init.py

from restapi.app import apiv1 as api
from restapi.resource.apiv1.user import UserResource

api.add_resource(
	UserResource,
	"/users",
	methods=["GET", "POST"],
	endpoint="users"  # It will be shown in response as key name.
)

Everytime you want to add or change an endpoint like "/users" you should add_resource() by calling api object with desired arguments, for example:

• The first argument is the class that contains get, post or put methods definitions, that is present in user.py file
• The second argument is the endpoint url itself
• The 3rd argument shows the methods that api endpoint accepts for incoming requests

Step 4 in detail:

user.py

from flask_restful import Resource
from restapi.util import jsonify

class UserResource(Resource):

	def get(self, user_id=None):
		"""
		GET /users --> Get list of users.
		GET /users/<user_id> --> Get the user.
		"""
		if user_id is None:
			return jsonify({
			"users": "test without user_id"
			})
		else:
			return jsonify({
			"users": "test with user_id"
			})

	def post(self):
		"""
		POST /users --> Create new user.
		POST /users/<user_id> --> Not allowed.
		"""
		pass

	def patch(self, user_id):
		"""
		PATCH /users --> Not allowed.
		PATCH /users/<user_id> --> Update the user.
		"""
		pass

	def delete(self, user_id):
		"""
		DELETE /users --> Not allowed.
		DELETE /users/<user_id> --> Delete the user.
		"""
		pass

In step 3 we called UserResource as the class for GET requests, now with modifying get definition you can call other functions to do whatever you want and finally take back a response, it means you can import other packages in user.py file and use them in "get" method definition by calling

Finally to test the created api:

$ curl -H "Content-Type: application/json" -X GET http://127.0.0.1:8080/api/v1/users

{ "users": "test without user_id", "message": "OK", "code": 100 }