cache.py

# A barebones cache with a TTL

import threading
import time

class Cache:
  def __init__(self):
    self.cache = {}
    # 4 seconds
    self.TTL = 4
  def get(self, key):
    return self.cache[key]
  def put(self, key, value):
    if key not in self.cache:
      self.cache[key] = value
      threading.Timer(self.TTL, self.invalidateCacheKey, [key]).start()
  def invalidateCacheKey(self, key):
    if key in self.cache:
      del self.cache[key]
      
c = Cache()
c.put("mykey", "myvalue")

for i in range(1, 10):
  time.sleep(1)
  print(c.get("mykey"))