Any AOP support library for Python?

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See S.Lott’s link about Python decorators for some great examples, and see the defining PEP for decorators.

Python had AOP since the beginning, it just didn’t have an impressive name.
In Python 2.4 the decorator syntax was added, which makes applying decorators very nice syntactically.

Maybe if you want to apply decorators based on rules you would need a library, but if you’re willing to mark the relevant functions/methods when you declare them you probably don’t.

Here’s an example for a simple caching decorator (I wrote it for this question):

import pickle, functools
def cache(f):
  _cache = {}
  def wrapper(*args, **kwargs):
    key = pickle.dumps((args, kwargs))
    if key not in _cache:
      _cache[key] = f(*args, **kwargs) # call the wrapped function, save in cache
    return _cache[key] # read value from cache
  functools.update_wrapper(wrapper, f) # update wrapper's metadata
  return wrapper

import time
@cache
def foo(n):
  time.sleep(2)
  return n*2

foo(10) # first call with parameter 10, sleeps
foo(10) # returns immediately

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