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

1 vote285 views1 answer
Django manger
Python
0 vote266 views1 answer
I += 1 meaning in python
Python
15 votes211 views2 answers
Python copy image to clipboard
Python
0 vote286 views1 answer
Python Hewwo wowwd
Python
0 vote269 views1 answer
Python if type dict
Python
1 vote258 views1 answer
Pandas row where value in list
Python
12 votes270 views2 answers
Python string to hex
Python
1 vote250 views1 answer
Print every element in list python outside string
Python
1 vote304 views1 answer
Python divide one column by another
Python
0 vote294 views1 answer
How to submit two forms in django
Python