I came across an interesting recent addition to the Python language (as of Python 2.4). They are called decorators. Decorators are Python objects that can register, annotate, and/or wrap a Python function or method. They are primarily used to achieve code reuse. This approach to programming struck me as being very similar to Aspect oriented programming. A decorator is a callable object (like a function) that accepts one argument—the function being decorated. The return value of the decorator replaces the original function definition. One use I found useful, was timing how long function calls actually take:
import time
def print_timing(func):
def wrapper(*arg):
t1 = time.time()
res = func(*arg)
t2 = time.time()
print '%s took %0.3f ms' % (func.func_name, (t2-t1)*1000.0)
return res
return wrapper
# declare the @ decorator just before the function, invokes print_timing()
@print_timing
def myFunction(n):The following page discusses a number of other uses of this pattern (well worth a read). http://www.phyast.pitt.edu/~micheles/python/documentation.html