Create API Routes

We'll be using Flask-RESTX to create our API routes. The API routes will look like these:

• For daily or custom dates:/api/v1/get-horoscope/daily?day=today&sign=capricorn or api/v1/get-horoscope/daily?day=2022-12-14&sign=capricorn
• For weekly: api/v1/get-horoscope/weekly?sign=capricorn
• For monthly: api/v1/get-horoscope/monthly?sign=capricorn

We have two query parameters in the URLs: day and sign. The day parameter can take values like today, yesterday, or custom dates like 2022-12-14. The sign parameter will take the zodiac sign name which can be in uppercase or lowercase, it won't matter.

To parse the query parameters from the URL, Flask-RESTX has built-in support for request data validation using a library similar to argparse called reqparse. To add arguments in the URL, we'll use add_argument method of the RequestParser class.

parser = reqparse.RequestParser()
parser.add_argument('sign', type=str, required=True)

The type parameter will take the type of parameter. The required=True makes the query parameter mandatory to be passed.

Now, we need another query parameter day. But this parameter will be used only in the daily horoscope URL.

Instead of rewriting arguments we can write a parent parser containing all the shared arguments and then extend the parser with copy().

parser_copy = parser.copy()
parser_copy.add_argument('day', type=str, required=True)

The parser_copy will not only contain day, but also sign. That is what we'll require for the daily horoscope.

The main building blocks provided by Flask-RESTX are resources. Resources are built on top of Flask pluggable views, giving you easy access to multiple HTTP methods just by defining methods on your resource.

Let's create the DailyHoroscopeAPI class that inherits the Resource class from flask_restx.

@ns.route('/get-horoscope/daily')
class DailyHoroscopeAPI(Resource):
    '''Shows daily horoscope of zodiac signs'''
    @ns.doc(parser=parser_copy)
    def get(self):
        args = parser_copy.parse_args()
        day = args.get('day')
        zodiac_sign = args.get('sign')
        try:
            zodiac_num = ZODIAC_SIGNS[zodiac_sign.capitalize()]
            if "-" in day:
                datetime.strptime(day, '%Y-%m-%d')
            horoscope_data = get_horoscope_by_day(zodiac_num, day)
            return jsonify(success=True, data=horoscope_data, status=200)
        except KeyError:
            raise NotFound('No such zodiac sign exists')
        except AttributeError:
            raise BadRequest(
                'Something went wrong, please check the URL and the arguments.')
        except ValueError:
            raise BadRequest('Please enter day in correct format: YYYY-MM-DD')

The @ns.route() decorator sets the API route. Inside the DailyHoroscopeAPI class, we have the get method that will handle the GET requests. The @ns.doc() decorator will help us add the query parameters on the URL.

To get the values of query parameters, we'll use the parse_args() method that will return us a dictionary like this:

{'sign': 'capricorn', 'day': '2022-12-14'}

We can then get the values using the keys day and sign.

As defined in the beginning, we'll have a ZODIAC_SIGNS dictionary. We use a try-except block to handle the request. If the zodiac sign is not in the dictionary, a KeyError Exception is raised. In that case, we respond with a NotFound error (Error 404).

Also, if the day parameter has a hyphen in it, we try to match the date format with YYYY-MM-DD. If it's not in that format, we raise a BadRequest error (Error 400). If the day doesn't contain a hyphen, we directly call the get_horoscope_by_day() method with the sign and day arguments.

If some gibberish is passed as the parameter value, an AttributeError is raised. In that case, we raise a BadRequest error.

The other two routes are also quite similar to the above one. The difference is, we don't need a day parameter here. So, instead of using parser_copy, we'll use parser here.

@ns.route('/get-horoscope/weekly')
class WeeklyHoroscopeAPI(Resource):
    '''Shows weekly horoscope of zodiac signs'''
    @ns.doc(parser=parser)
    def get(self):
        args = parser.parse_args()
        zodiac_sign = args.get('sign')
        try:
            zodiac_num = ZODIAC_SIGNS[zodiac_sign.capitalize()]
            horoscope_data = get_horoscope_by_week(zodiac_num)
            return jsonify(success=True, data=horoscope_data, status=200)
        except KeyError:
            raise NotFound('No such zodiac sign exists')
        except AttributeError:
            raise BadRequest('Something went wrong, please check the URL and the arguments.')


@ns.route('/get-horoscope/monthly')
class MonthlyHoroscopeAPI(Resource):
    '''Shows monthly horoscope of zodiac signs'''
    @ns.doc(parser=parser)
    def get(self):
        args = parser.parse_args()
        zodiac_sign = args.get('sign')
        try:
            zodiac_num = ZODIAC_SIGNS[zodiac_sign.capitalize()]
            horoscope_data = get_horoscope_by_month(zodiac_num)
            return jsonify(success=True, data=horoscope_data, status=200)
        except KeyError:
            raise NotFound('No such zodiac sign exists')
        except AttributeError:
            raise BadRequest('Something went wrong, please check the URL and the arguments.')

Now our routes are done.