Store the results of the decorated function for fast lookup

memorize.py

from functools import wraps

 
def memorize(func):
  """Store the results of the decorated function for fast lookup """
  # Store results in a dict that maps arguments to results  
  cache = {}

  @wraps(func)
  def wrapper(*args, **kwargs):
    # If these arguments haven't been seen before,
    if (args, kwargs) notin cache: # Call func() and store the result.      
      cache[(args, kwargs)] = func(*args, **kwargs)
    return cache[(args, kwargs)]
  return wrapper

@memorize
def slow_function(a, b):  
  print('Sleeping...')  
  time.sleep(5)
  return a + b

# First time
slow_function(3, 4) 
'''
Sleeping...
7
'''

# Second time
slow_function(3, 4)
# 7