Pythonic Rest time service using Flask

rest-time.py

#!/usr/bin/env python3
#
# REQUIREMENTS
#
# Flask-RESTful  0.3.8
# pyOpenSSL      19.1.0
#

import datetime
import time

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


## Tests:
## Install curl: apt install curl
#
# curl https://127.0.0.1:4443/api/time
#
# curl https://127.0.0.1:4443/api/time?format=rfc2822
#
# curl https://127.0.0.1:4443/api/time?format=datetime
#
# curl https://127.0.0.1:4443/api/time?format=ctime
#
# curl --header "Content-Type: application/json" --request POST --data '{"format": "rfc2822"}' "http://127.0.0.1:4443/api/time"
#

class TIME_FORMAT:
    UNIX = "unix"
    RFC2822 = "rfc2822"
    DATETIME = "datetime"
    CTIME = "ctime"


class TimeService(Resource):
    NAME = "/api/time"

    FORMAT_LIST = "{}, {}, {}, {}".format(
        TIME_FORMAT.UNIX,
        TIME_FORMAT.RFC2822,
        TIME_FORMAT.DATETIME,
        TIME_FORMAT.CTIME
    )

    def __init__(self):
        self.parser = reqparse.RequestParser()
        self.parser.add_argument("format", type=str, required=False,
                                 help="Accept values: {}".format(TimeService.FORMAT_LIST))

    def get(self):
        return self.process_request()

    def post(self):
        return self.process_request()

    @staticmethod
    def fmt_unix():
        unix_time = time.time()
        unix_sec = int(unix_time)
        unix_usec = int((unix_time - unix_sec) * 1e6)
        return {"sec": unix_sec, "usec": unix_usec}

    @staticmethod
    def fmt_rfc2822():
        time_value = time.strftime("%a, %d %b %Y %H:%M:%S +0000", time.gmtime())
        return {"time": time_value}

    @staticmethod
    def fmt_datetime():
        time_value = "{}".format(datetime.datetime.now())
        return {"time": time_value}

    @staticmethod
    def fmt_ctime():
        time_value = time.ctime()
        return {"time": time_value}

    def process_request(self):
        args = self.parser.parse_args()
        ret_val = {}
        if args["format"] == TIME_FORMAT.UNIX or args["format"] == None:
            # Default format option
            return TimeService.fmt_unix()

        elif args["format"] == TIME_FORMAT.RFC2822:
            return TimeService.fmt_rfc2822()

        elif args["format"] == TIME_FORMAT.DATETIME:
            return TimeService.fmt_datetime()

        elif args["format"] == TIME_FORMAT.CTIME:
            return TimeService.fmt_ctime()

        else:
            return {"error": "Invalid format '{}'".format(args["format"])}


def main():
    app = Flask(__name__)
    api = Api(app)
    api.add_resource(TimeService, TimeService.NAME)
    app.run(host="0.0.0.0", port=4443, ssl_context="adhoc", debug=True)


if __name__ == "__main__":
    main()