Python: Flask Cache for a range of time

Question

My Flask app, will get data from an url only from certain time. If it is outside the range of time, it will used the last query data from the url that save in Cache. Outside the range of time, the url will return no data. Thus, I want to reuse the last data in cache

from flask_app import app
from flask import jsonify,abort,make_response,request
from flask.ext.sqlalchemy import SQLAlchemy
from flask.ext.cache import Cache
from datetime import datetime, time

app.config['CACHE_TYPE'] = 'simple'
app.cache = Cache(app)

@app.route('/top', methods=['GET'])
@app.cache.cached(timeout=60)
def top():
    now = datetime.now()
    now_time = now.time()
    if now_time >= time(10,30) and now_time <= time(16,30):
       print "within time, use data save in cache"
       # function that use last data query from url, save in cache
    else:
       page = requests.get('http://www.abvfc.com')
       data = re.findall(r'items:(.*)',page.content)
return jsonify(data)

The problem is I can't get the last Cache data. If there is no access to the api /top in the last 60 seconds, there will be no data.

1. Cache the data one minutes before the url return no data at 16.30

2. User can use the cache data outside range of time

I am not familiar with cache, so may be my current idea is not the best way.

Answer 1

i am not a flask user but perhaps this is your wanted decorator

def timed_cache(cache_time:int, nullable:bool=False):
    result = ''
    timeout = 0
    def decorator(function):
        def wrapper(*args, **kwargs):
            nonlocal result
            nonlocal timeout

            if timeout <= time.time() or not (nullable or result):
                result = function(*args, **kwargs)
                timeout = time.time() + cache_time

            return result
        return wrapper
    return decorator