server.py

import json
from http.server import HTTPServer, BaseHTTPRequestHandler
from urllib.parse import urlparse, parse_qs

PORT = 5000

class API():
    def __init__(self):
        self.routing = { "GET": { }, "POST": { } }
    
    def get(self, path):
        def wrapper(fn):
            self.routing["GET"][path] = fn
        return wrapper

    def post(self, path):
        def wrapper(fn):
            self.routing["POST"][path] = fn
        return wrapper

api = API()

example_data = {
    "items": [
        { "id": 1000, "name": "cat", "description": "cat is meowing" },
        { "id": 1001, "name": "dog", "description": "dog is barking" },
        { "id": 1002, "name": "bird", "description": "bird is singing" }
    ]
}

@api.get("/")
def index(_):
    return { 
        "name": "Python REST API Example",
        "summary": "This is simple REST API architecture with pure Python",
        "actions": [ "add", "delete", "list", "search" ],
        "version": "1.0.0"
    }


@api.get("/list")
def list(_):
    return {
        "count": len(example_data["items"]),
        "items": example_data["items"]
    }

@api.get("/search")
def search(args):
    q = args.get("q", None)

    if q is None:
        return { "error": "q parameter required" }
    else:
        results = []
        for item in example_data["items"]:
            if item["name"].count(q) > 0:
                results.append(item)
        return { "count": len(results), "items": results }


@api.post("/add")
def add(args):
    id = example_data["items"].copy().pop()["id"] + 1
    name = args.get("name", None)
    description = args.get("description", None)

    if name is None or description is None:
        return { "error": "name and description are required parameters" }
    else:
        item = { "id": id, "name": name, "description": description }
        example_data["items"].append(item)
        return item


@api.post("/delete")
def delete(args):
    id = args.get("id", None)
    if id is None:
        return { "error": "id parameter required" }
    else:
        item_deleted = False

        for item in example_data["items"]:
            if item["id"] == id:
                example_data["items"].remove(item)
                item_deleted = True
                break
        
        if item_deleted:
            return { "deleted": id }
        else:
            return { "error": f"item not found with id {id}" }


if __name__ == "__main__":
    class ApiRequestHandler(BaseHTTPRequestHandler):
        global api
        
        def call_api(self, method, path, args):
            if path in api.routing[method]:
                try:
                    result = api.routing[method][path](args)
                    self.send_response(200)
                    self.end_headers()
                    self.wfile.write(json.dumps(result, indent=4).encode())
                except Exception as e:
                    self.send_response(500, "Server Error")
                    self.end_headers()
                    self.wfile.write(json.dumps({ "error": e.args }, indent=4).encode())
            else:
                self.send_response(404, "Not Found")
                self.end_headers()
                self.wfile.write(json.dumps({"error": "not found"}, indent=4).encode())

        def do_GET(self):
            parsed_url = urlparse(self.path)
            path = parsed_url.path
            args = parse_qs(parsed_url.query)
            
            for k in args.keys():
                if len(args[k]) == 1:
                    args[k] = args[k][0]
            
            self.call_api("GET", path, args)

        def do_POST(self):
            parsed_url = urlparse(self.path)
            path = parsed_url.path
            if self.headers.get("content-type") != "application/json":
                self.send_response(400)
                self.end_headers()
                self.wfile.write(json.dumps({
                    "error": "posted data must be in json format"
                }, indent=4).encode())
            else:
                data_len = int(self.headers.get("content-length"))
                data = self.rfile.read(data_len).decode()
                self.call_api("POST", path, json.loads(data))


    httpd = HTTPServer(('', PORT), ApiRequestHandler)
    print(f"Application started at http://127.0.0.1:{PORT}/")
    httpd.serve_forever()