The simplest crud application one can make with flask and an in memory storage. Is not perfect, but shows the idea on how to create it faster.

crud.py

from typing import Any, Dict, List
from flask import Flask, jsonify, request


app = Flask(__name__)


# In Memory data storage, or a list.
students: List[Dict[str, Any]] = []


@app.route("/students", methods=["GET", "POST"])
def index():
    """
    Main student route.
    
    GET -> retrieve all students.
    POST -> create a new student, no validation is required here.
    """
    if request.method == "POST":
        students.append(request.json)  # type: ignore

        return jsonify(), 201

    return jsonify({"students": students})


@app.route("/students/<int:id>", methods=["GET", "PUT", "DELETE"])
def get_one_record(id: int):
    """
    Deals with a single student.
    
    GET -> receives an id (position on the array) and returns it.
    PUT -> update the dictionary where the user is stored.
    DELETE -> remove that particular student from the list.
    """
    try:
        student = students[id]
    except IndexError:
        return jsonify({"details": "Student not found"}), 404

    if request.method == "GET":
        return jsonify({"student": student})

    if request.method == "PUT":
        student.update(request.json)  # type: ignore
        return jsonify(), 204

    if request.method == "DELETE":
        students.remove(student)
        return jsonify(), 204

Can I run it locally on my machine?

Sure, follow the steps below to make it stonks! By the way, the commands are for Linux, so, if you're a windows user you must adapt the widget thingy.

pip install Flask gunicorn
wget -O crud.py https://gist.githubusercontent.com/igormcsouza/3b16dafd17a24119ba70e03ed3b4db01/raw/1938686f0c7a383a6ce6c23cce0c0e3ba7f5a50c/crud.py
gunicorn crud:app --bind 0.0.0.0:8000 --reload