Python CLI

cli.py

import argparse
from dataclasses import dataclass, field, asdict
import requests
import shutil
from datetime import datetime
import logging

class ValidationException(Exception):
    pass

@dataclass
class Vaccination:
    manufacturer: str
    date: str

    def __init__(self):
        try:
            date = datetime.strptime(self.date, "%Y-%m-%d")
        except Exception:
            raise ValidationException("Vaccination date should be in format YYYY-MM-DD.")
        if date > datetime.today():
            raise ValidationException("Vaccination date should not be a future date.")
        if self.manufacturer.lower() not in ["pfizer","moderna","astrazeneca","janssen","sinovac"]:
            raise ValidationException("Your vaccine manufacturer is not approved.")

@dataclass
class QRCode:
    name: str
    birth: str
    vaccine: list[Vaccination] = field(default_factory=list)

def generate_qr_code(qr_code):
    code = asdict(qr_code)
    res = requests.get(f"http://api.qrserver.com/v1/create-qr-code/?data={code}", stream=True)
    if res.status_code == 200:
        with open("qr_code.png", "wb") as f:
            res.raw.decode_content = True
            shutil.copyfileobj(res.raw, f)
        return "QR code has been generated."
    else:
        raise Exception("QR code cannot be generated by QR Code Generator API.")


def main():
    parser = argparse.ArgumentParser(description="Generate your vaccination QR code.")
    parser.add_argument("-n", "--name", type=str, help="Your name", required=True)
    parser.add_argument("-b", "--birth", type=str, help="Your birthday in YYYY-MM-DD format", required=True)
    parser.add_argument("-m", "--manufacturer", type=str, nargs="+", help="The vaccine manufacturer", required=True, choices=[
            "pfizer","moderna","astrazeneca","janssen","sinovac"])
    parser.add_argument("-d", "--date", type=str, nargs="+", help="The date of vaccination", required=True)
    args = parser.parse_args()
    
    if len(args.manufacturer) != len(args.date):
        logging.error(
            "The number of vaccine manufacturer doesn't match with the number of vaccine dates."
        )
        exit(1)
    
    qr_code = QRCode(name=args.name, birth=args.birth, vaccine=[Vaccination(args.manufacturer[i], args.date[i]) for i in range(len(args.date))])
    generate_qr_code(qr_code)

if __name__ == "__main__":
    try:
        main()
    except ValidationException as e:
        logging.error(e)
    except Exception as e:
        logging.exception(e)