decoratorExamples.py

import time


def donothingDecorator(f):
  """ Make a function returning some string return it prepended with the string's length. """
  def wrapper(*args, **kwargs):
    #print("ogwell")
    returnvalue = str(f(*args, **kwargs))
    return str(len(returnvalue)) + " " + returnvalue
  return wrapper


@donothingDecorator
def returnStuff(n):
  return str(n)


print(returnStuff("hello"))


cache = {}
def memoized(f):
  """ Cache a function's return value, and use it, if available. """
  def wrapper(*args, **kwargs):
    key = f.__name__ + str(args[0])
    if key in cache:
      return cache[key]
    else:
      cache[key] = f(*args, **kwargs)
      return cache[key]
  return wrapper

def fib1(n):
  if n > 2:
    return fib1(n-1) + fib1(n-2)
  return 1

@memoized
def fib2(n):
  if n > 2:
    return fib2(n-1) + fib2(n-2)
  return 1

# benchmark

n = 30

runcount = 10

t1 = time.time()

for i in range(runcount):
  fib1(n)

t2 = time.time()
for i in range(runcount):
  fib2(n)

t3 = time.time()

print(t2 - t1)
print(t3 - t2)