Python Flask REST API Tutorial on Medium. 🔗 https://codeburst.io/this-is-how-easy-it-is-to-create-a-rest-api-8a25122ab1f3

app.py

from flask import Flask
from flask_restful import Api, Resource, reqparse

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

users = [
    {
        "name": "Nicholas",
        "age": 42,
        "occupation": "Network Engineer"
    },
    {
        "name": "Elvin",
        "age": 32,
        "occupation": "Doctor"
    },
    {
        "name": "Jass",
        "age": 22,
        "occupation": "Web Developer"
    }
]

class User(Resource):
    def get(self, name):
        for user in users:
            if(name == user["name"]):
                return user, 200
        return "User not found", 404

    def post(self, name):
        parser = reqparse.RequestParser()
        parser.add_argument("age")
        parser.add_argument("occupation")
        args = parser.parse_args()

        for user in users:
            if(name == user["name"]):
                return "User with name {} already exists".format(name), 400

        user = {
            "name": name,
            "age": args["age"],
            "occupation": args["occupation"]
        }
        users.append(user)
        return user, 201

    def put(self, name):
        parser = reqparse.RequestParser()
        parser.add_argument("age")
        parser.add_argument("occupation")
        args = parser.parse_args()

        for user in users:
            if(name == user["name"]):
                user["age"] = args["age"]
                user["occupation"] = args["occupation"]
                return user, 200
        
        user = {
            "name": name,
            "age": args["age"],
            "occupation": args["occupation"]
        }
        users.append(user)
        return user, 201

    def delete(self, name):
        global users
        users = [user for user in users if user["name"] != name]
        return "{} is deleted.".format(name), 200
      
api.add_resource(User, "/user/<string:name>")

app.run(debug=True)

Thanks for you help! I successfully use c socket to test it.
https://github.com/JamesChan21/Flask_And_C_Socket

Why is it taking a GET request. Its nowhere specified in the code to take default GET function
How can we change it to another function(ex:POST)

http://127.0.0.1:5000/user/Marvin?age=29

^ That is the way you can do it in the URL.
You can also do it in the following way:
Change from "GET" to PUT.
Click on PARAMS
Under "Key" fill in the attribute of choice (age, occupation, etc.)
Under Value, fill in desired value (for example, 30).

Then, click on SEND.

The following should be displayed in the body:

Why is it taking a GET request. Its nowhere specified in the code to take default GET function
How can we change it to another function(ex:POST)

Note you are calling User class in api.add_resource(User, "/api/user/<string:name>"). As you initialize HTTP call it will make a request for HTTP GET method. See console debug output:
127.0.0.1 - - [20/Nov/2019 17:31:41] "GET /api/user/Jass HTTP/1.1" 200 -

Three ways how to interact with data

Using CURL, you can add new user by using above posted:
curl --request POST --url http://127.0.0.1:5000/api/user/George

You can manipulate the data by using
curl -X PUT -H "Content-Type: application/json" -d '{"age":"23"}' http://127.0.0.1:5000/api/user/George

Notice: I am using different access path with /api/user/

---

Second way is by using Python's requests module, such as:
import requests
req = requests.get('http://127.0.0.1:5000/api/user/Nicholas')
req.text
req.json()

POST request:
requests.post('http://127.0.0.1:5000/api/user/Mike', data = {'age':57})

---

The third way is via user interface such as Insomia or Postman

I hope this helps. Good luck!

Hi colleagues. How to run this with parameters from the command line host and port?

Thank u!

Hi colleagues. How to run this with parameters from the command line host and port?

Thank u!

Hi mate, you may use a Python built-in library called argparse to specify command line arguments.

Is there anyway to show a list of users that already exist?