# vim: set expandtab ts=4 sw=4 filetype=python:

import signal
import logging, logging.config
from random import choice

logging.config.fileConfig("debuglogger.cfg")
log = logging.getLogger("debuglogger")

companions = ['Sara Jane Smith', 'Leela', 'Rose Tyler']

alphabetized_companions = ['Leela', 'Sara Jane Smith', 'Rose Tyler']

def extract(s):
    "Return a string to sort by."
    if ' ' in s:
        return s.split(' ')[-1]
    else:
        return s

def companion_compare(a, b):                                    
   "Use function extract to compare a and b."
   if extract(a) < extract(b):
       return -1
   elif extract(a) > extract(b):
       return 1
   else:
       return 0

def f(a, b):
    "Returns a minus b"
    return a - b

def debuglogger(f):
    def logged(*args, **kwargs):
        log.debug("args is %s and kwargs is %s." 
                  % (args, kwargs))
        results = f(*args, **kwargs)
        log.debug("results from calling %s is %s." 
                  % (f.func_name, results))
        return results
    return logged

def add_n(n):
    "Return a decorator that adds n."

    def dec(f):
        "This is the decorator"

        def h(*args, **kwargs):
            "This is the decorated version of f"
            return n + f(*args, **kwargs)

        return h

    return dec

def A():
    for x in 'wash', 'flea dip', 'dry':
        print x

def B():
    A()
    print 'toothbrushing'

def B2():
    "Like B, but doesn't call A first"
    print 'toothbrushing'

def C():
    for x in 'wash', 'dry','hairball medicine':
        print x

def D():
    C()
    print 'A ridiculous haircut'

class Pet(object):
    "Parent for Cat and Dog"

    def groom(self, package):
        raise NotImplementedError("subclasses must define this...")

class Cat(Pet):
    "I am a cat"

    def groom(self, package):

        print "calling Cat.groom"

        if isinstance(package, Standard):
            C()
        else:
            D()

class Dog(Pet):
    "I am a dog"

    def groom(self, package):
        if isinstance(package, Standard):
            A()
        else:
            B()

class Package(object):
    "Parent of standard and premium"

class Standard(Package):
    "The cheapo way out"

class Premium(Package):
    "You have too much money"

def customer_shows_up():
    return Cat()

def customer_chooses():
    return Premium()

def returns_sometimes():
    "Return immediately (99%) or hang forever (1%)."

    if choice(range(1, 101)) != 1:
        return 

    else: 
        i = 1
        while "forever": 
            i += 1
            if i == 1000000:
                i = 0

class TimeoutException(Exception): 
    "Indicates that the function has taken too long."

def handle_alarm(*args):
    logging.error("Timeout!")
    raise TimeoutException(*args)

def with_timeout(seconds_to_wait, on_timeout):

    """
    After seconds_to_wait seconds, we interrupt the function and instead call
    on_timeout.
    """

    def dec(f, *args, **kwargs):

        # Set the handler for the alarm signal.
        signal.signal(signal.SIGALRM, handle_alarm)

        # Schedule an alarm for two seconds in the future.
        signal.alarm(seconds_to_wait)
    
        try:
            # Call the function.
            y = f(*args, **kwargs)

            # If the function returned, then cancel the alarm.
            signal.alarm(0)

            # Now return what we got.
            return y 

        except TimeoutException, ex:
            on_timeout(ex)

    return dec

def out_of_time(ex):

    "Clean up and move on."

    log.debug("We got unlucky.")
    log.debug("ex.args is %s." % str(ex.args))


__id__ = "$Id: decoratortalk.py 106 2008-07-25 03:45:15Z matt $"