python decorators

"""
DECORATORS
PEP 318
Introduced in Python 2.4
"""

#-----------------------------------------
# simple decorator
#-----------------------------------------
def log(f):
    def new_f(*args, **kwargs):
        print f.__name__, ': called'
        print args, kwargs
        f(*args, **kwargs)
        print f.__name__, ': end of call'

    return new_f

class Simple(object):
    @log
    def do(self, *args, **kwargs):
        print '...done'


#-----------------------------------------
# decorator without sugar
#-----------------------------------------
class NoMagic(object):
    def do(self, *args, **kwargs):
        print '...done'
    do = log(do)


#-----------------------------------------
# decorator with arguments
#-----------------------------------------
def prefix(text):
    def fn(method):
        def new_fn(*args, **kwargs):
            print text,
            method(*args, **kwargs)
        #rename the method to be the same as the decorated one
        #new_fn.__name__ = method.__name__
        return new_fn

    return fn

class Args(object):
    @prefix('wait for it: ')
    def do(self, *args, **kwargs):
        print '...done'


#-----------------------------------------
# decorator with arguments and no sugar
#-----------------------------------------
class NoMagicArgs(object):
    def do(self, *args, **kwargs):
        print '...done'
    do = prefix('wait for it: ')(do)


#-----------------------------------------
# chaining decorators
#-----------------------------------------
class Chain(object):
    @log
    @prefix("I'm chaind but still: ")
    def do(self, *args, **kwargs):
        print '...done'