Task: Write APIs to Demonstrate Various HTTP Methods

Context: Develop APIs to showcase the functionality of different HTTP methods: GET, POST, PUT, PATCH, and DELETE. Ensure that each method returns appropriate response status codes and response bodies.

from flask import Flask, request, jsonify

app = Flask(name)

Sample data stored in a dictionary

users = {

1: {"name": "Arpita", "age": 25},

2: {"name": "Aditya", "age": 30} }

1 GET - Retrieve all users

@app.route('/users', methods=['GET'])

def get_users():

return jsonify(users), 200

GET - Retrieve a specific user by ID

@app.route('/users/int:user_id', methods=['GET'])

def get_user(user_id):

if user_id in users:

return jsonify({user_id: users[user_id]}), 200

return jsonify({"message": "User not found"}), 404

2 POST - Add a new user

@app.route('/users', methods=['POST'])

def create_user():

data = request.get_json()

if "name" not in data or "age" not in data:

return jsonify({"message": "Missing required fields"}), 400

new_id = max(users.keys()) + 1 # Generate new user ID

users[new_id] = {"name": data["name"], "age": data["age"]}

return jsonify({new_id: users[new_id]}), 201

3 PUT - Update an existing user (replace completely)

@app.route('/users/int:user_id', methods=['PUT'])

def update_user(user_id):

data = request.get_json()

if "name" not in data or "age" not in data:

return jsonify({"message": "Missing required fields"}), 400

if user_id in users:

users[user_id] = {"name": data["name"], "age": data["age"]}

return jsonify({user_id: users[user_id]}), 200

return jsonify({"message": "User not found"}), 404

4 PATCH - Partially update a user

@app.route('/users/int:user_id', methods=['PATCH'])

def patch_user(user_id):

data = request.get_json()

if user_id in users:

users[user_id].update(data)  # Update only provided fields

return jsonify({user_id: users[user_id]}), 200

return jsonify({"message": "User not found"}), 404

5 DELETE - Remove a user

@app.route('/users/int:user_id', methods=['DELETE'])

def delete_user(user_id):

if user_id in users:

del users[user_id]

return jsonify({"message": "User deleted"}), 200

return jsonify({"message": "User not found"}), 404

if name == 'main':

app.run(debug=True)

1 Route : /users

Method : GET

Functionality : Returns all users as Json response.

Response code : 200 ok

Route : /users/<usre_id>

Method : GET

Functionality : fetches a user by user_id

Response code :

 200 ok ( if user exists)

 400 not found (if the user id is missing)

2 Route : /users

Method : POST

Functionality : Add a new user

Steps:

 Extract Json request data

  Validate if "name" & "age" exist

  Assigns a new unique  user_id

 Adds the user to the users dictionary 

Response code :

 200  ok (Created if successful)

 400  Bad request (if required  fields are missing)

3 Route : /users/<usre_id>

Method : PUT

Functionality : full updates the users

Steps:

Checks if user_id is exists

Validate input data

Replace entire user record

Response code :

200 ok (if successful)

404 not found (if user doesn't  exist)

400  Bad request (if data is missing)

4 Route : /users/<usre_id>

Method : PATCH

Functionality : Partially update user details

Steps :

 check if user_id exists

 update only provided fields 

Response code :

 200 ok (if successful)

 404 not found (if user doesn't exists)

5 Route : /users/<usre_id>

Method : DELETE

Functionality : delete user from dictionary

Response code :

 200 ok (if deleted  successful)

 404 not found (user not found)