Python function cache

# Example use - Decorator code below -----------------------------
import time

@cache(ttl=timedelta(minutes=3), max_entries=300)
def add(a, b):
    time.sleep(2)
    return a + b

@cache()
def substract(a, b):
    time.sleep(2)
    return a - b
  
  
# Decorator code -----------------------------
from datetime import datetime, timedelta

def cache(**kwargs):
  def decorator(function):
    # static function variable for cache, lazy initialization
    try: function.cache
    except: function.cache = {}
    def wrapper(*args):
        # if nothing valid in cache, insert something
        if not args in function.cache or datetime.now() > function.cache[args]['expiry']:
            if 'max_entries' in kwargs:
                max_entries = kwargs['max_entries']
                if max_entries != None and len(function.cache) >= max_entries:
                    now = datetime.now()
                    function.cache = { key: function.cache[key] for key in function.cache.keys() if function.cache[key]['expiry'] > now }
                    # if nothing is expired that is deletable, delete the first
                    if len(function.cache) >= max_entries:
                        del function.cache[next(iter(function.cache))]
            function.cache[args] = {'result': function(*args), 'expiry': datetime.max if 'ttl' not in kwargs else datetime.now() + kwargs['ttl']}

        # answer from cache
        return function.cache[args]['result']
    return wrapper
  return decorator

Source: stackoverflow.com

Similar codes

2 votes340 views1 answer
Python selenium move cursor to element
Python
1 vote395 views1 answer
Cookies in django
Python Django
-1 vote314 views1 answer
Python os file path
Python
1 vote402 views1 answer
How to pass header in requests
Python
3 votes395 views6 answers
Django login
Python Django
0 vote325 views1 answer
Change month name in python
Python
-1 vote323 views1 answer
Python unicode point to utf8 string
Python
0 vote357 views1 answer
Keras functional api embedding layer
Python
1 vote315 views1 answer
Plt.plot width line
Python
-1 vote321 views1 answer
Pip install not happening in python cmd
Python