Simple Memoization demo using Python decorators

memoize.py

''' Simple Memoization demonstration using decorators'''

#dictionary
global cached 
cached = {}

def cache(n):
    def wrap(f):
        def wrapped_f(*args):
            global cached
            cached['{0:s}'.format(str(args[0]))] = f(args[0])
        return wrapped_f
    return wrap
    

@cache(1)
def fact(n):
    prod = 1
    for i in xrange(1,n+1):
        prod = prod*i
        
    return prod
    
#entry point
if __name__ == '__main__':

    while True:
        n = input('Enter a number:: ')
        try:
            print 'Hit:: Factorial is:: {0:d}'.format(cached[str(n)])
        except KeyError:
            fact(n)
            print 'Miss:: Factorial is:: {0:d}'.format(cached[str(n)])


Sample Output:

Enter a number:: 5
Miss:: Factorial is:: 120
Enter a number:: 10
Miss:: Factorial is:: 3628800
Enter a number:: 5
Hit:: Factorial is:: 120
Enter a number:: 5
Hit:: Factorial is:: 120
Enter a number:: 6
Miss:: Factorial is:: 720