A Python decorators example

gistfile1.py

from functools import wraps

def cache(func):
  func.cache = None
  @wraps(func)
  def inner(*a, **k):
    if func.cache is None:
      func.cache = func(*a, **k)
    return func.cache
  return inner
  
def debug(func):
  @wraps(wraps)
  def inner(*a, **k):
    print(str(a) + str(k))
    return func(*a, **k)
  return inner

if '__main__'==__name__:
  @cache
  @debug
  def add(a, b):
    return a + b

  print(add(1, 2))
  print(add(3, 4))