FLASK.MD

Flask : [documentation]

Rest API with Python and Flask : REST stands for REpresentational State Transfer and is an architectural style used in modern web development. It defines a set or rules/constraints for a web application to send and receive data. REST API stands for Restful API, which allows the integration of applications or interaction with RESTful web services. New : FastAPI and use POSTMAN to test API. We know that there are six commonly used HTTP request methods, which are : GET, POST, PUT, DELETE, PATCH, HEAD.

@app.route('/', methods=['GET'])
@app.route('/', methods=['POST'])
@app.route('/', methods=['DELETE'])
@app.route('/', methods=['PUT'])

I have some experience with Flask and did few projects (example-work). I recently gave a workshop at AI-Makerspace, Digital Product School, Unternehmer Technische Universität München on flask, maps and ML. Tech Stack : [ Flask, JavaScript, Bootstrap, Mapbox, MongoDB, PyTorch ] and here is the code repository.

Flask Template Gallery :

Flask (basic) code ✔️	Flask (design+js) code ✔️	Flask (input) code ✔️	Flask (mapbox + mongoDB) code ✔️
Flask (3dmap - cesium + AR) code ✔️	Flask (deep learning - tf/pytorch) code ✔️	Flask (docker + gcloud) code ✔️

Deployment of Flask server : PythonAnywhere, Heroku, Digital Ocean, Virtual Machine from Google Cloud : Google App Engine, Google Cloud Run, AWS : Elastic Beanstalk, Azure IIS etc.

import json
from flask import Flask, request, jsonify

app = Flask(__name__)

@app.route('/', methods=['GET'])
def query_records():
    name = request.args.get('name')
    print name
    with open('/tmp/data.txt', 'r') as f:
        data = f.read()
        records = json.loads(data)
        for record in records:
            if record['name'] == name:
                return jsonify(record)
        return jsonify({'error': 'data not found'})

@app.route('/', methods=['PUT'])
def create_record():
    record = json.loads(request.data)
    with open('/tmp/data.txt', 'r') as f:
        data = f.read()
    if not data:
        records = [record]
    else:
        records = json.loads(data)
        records.append(record)
    with open('/tmp/data.txt', 'w') as f:
        f.write(json.dumps(records, indent=2))
    return jsonify(record)

@app.route('/', methods=['POST'])
def update_record():
    record = json.loads(request.data)
    new_records = []
    with open('/tmp/data.txt', 'r') as f:
        data = f.read()
        records = json.loads(data)
    for r in records:
        if r['name'] == record['name']:
            r['email'] = record['email']
        new_records.append(r)
    with open('/tmp/data.txt', 'w') as f:
        f.write(json.dumps(new_records, indent=2))
    return jsonify(record)
    
@app.route('/', methods=['DELETE'])
def delte_record():
    record = json.loads(request.data)
    new_records = []
    with open('/tmp/data.txt', 'r') as f:
        data = f.read()
        records = json.loads(data)
        for r in records:
            if r['name'] == record['name']:
                continue
            new_records.append(r)
    with open('/tmp/data.txt', 'w') as f:
        f.write(json.dumps(new_records, indent=2))
    return jsonify(record)

app.run(debug=True)

Resources: Flask Mega Tutrial, Build a blog platform with Flask: writing and showing posts, Flask documentation : a minimal application, The Ultimate Flask Course, REST APIs with Flask and Python, Flask RESTful, Python REST API Tutorial - Building a Flask REST API, Postman API Test Automation.