Flask-caching a function using blueprints

Question

I am doing an app and I am using the Blueprints structure. My code is running okay, but I got this error while trying to implment flask-caching into one function.

The error returned is: AttributeError: 'Blueprint' object has no attribute 'cache'

Does anybody has a light of solution in here to make the cache happens to this function?

Here is a piece of my code:

from flask import render_template, redirect, request, Blueprint
from cache import store_weather, number_of_views, cached_weather, cache
import json, requests

bp = Blueprint('bp', __name__, url_prefix="/weather")
main = Blueprint('main', __name__)

api_key = "42fbb2fcc79717f7601238775a679328"

@main.route('/')
def hello():

    views = 5
    max_views = number_of_views()
    return render_template('index.html', cached_weather=cached_weather, max_views=max_views, views=views)


@bp.route('/', methods=['GET'])
def weather():

    clean_list_cache()

    if request.args.get('max').isdigit():
        views = int(request.args.get('max'))
    else:
        views = 5

    try:
        city_name = request.args.get('city')

        if city_name not in cached_weather:
            
            uri = 'http://api.openweathermap.org/data/2.5/weather?q={city}&appid={key}'.format(city=city_name,key=api_key)
            # On that point, we bring the data from the Open Weather API
            rUrl = requests.get(uri)

            # The temperature of the Open Weather API is in Kelvin, so, we have to subtract 273.15 to transform
            # it into Celsius degrees
            temperature = str(round((json.loads(rUrl.content)['main'])['temp']-273.15))+" °C"
            name = json.loads(rUrl.content)['name']
            description = json.loads(rUrl.content)['weather'][0]['description']

            city_data = { "temp":temperature, "name":name, "desc":description }

            store_weather(city_data)

        max_views = number_of_views(views)

        return render_template('weather.html',  cached_weather = cached_weather, error_rec_city = False, max_views=max_views, views=views)

    except KeyError:
        max_views = number_of_views(views)
        return render_template('weather.html',  cached_weather=cached_weather, error_rec_city = True, max_views=max_views, views=views)


@bp.cache.cached(timeout=30, key_prefix='list_cache')
def clean_list_cache():
    cached_weather.clear()

Answer 1

The error occurs, as you are trying to call cache on your blueprint: @bp.cache.cached. An example from the docs how to use cache is:

@app.route("/")
@cache.cached(timeout=50)
def index():
    return render_template('index.html')

So you have to squeeze the cache decorator between your app decorator and the function