Decorators examples in python.

decorators.py

from time import time

# Decoratoring with a class
class Benchmark(object):
    def __init__(self, function):
        self.function = function

    def __call__(self, *args, **kwargs):
        t1 = time()
        result = self.function(*args, **kwargs)
        t2 = time()

        diff = t2 - t1
        measure = "sec(s)"

        if diff < 1:
            measure = "ms"
            diff *= 1000

        print "Execution time: %.2f %s" % (diff, measure)
        return result

# Decoratoring with a function
def benchmark(function):
    def _benchmark(*args, **kwargs):
        t1 = time()
        result = function(*args, **kwargs)
        t2 = time()

        diff = t2 - t1
        measure = "sec(s)"

        if diff < 1:
            measure = "ms"
            diff *= 1000

        print "Execution time: %.2f %s" % (diff, measure)
        return result
    return _benchmark

usage.py

from decorators import *

# Class decorator example
@Benchmark
def take_time(n):
    for i in xrange(0, n):
        pass

# Function decorator example
@benchmark
def take_time2(n):
    for i in xrange(0, n):
        pass

take_time(1) #=> Execution time: 0.00 ms
take_time(100000000) #=> Execution time: 3.01 sec(s)

take_time2(1) #=> Execution time: 0.00 ms
take_time2(100000000) #=> Execution time: 3.01 sec(s)