def deco(func):     print 'before func'     return func def myfunc():     print 'myfunc() called'   myfunc = deco(myfunc)

def deco(func):     print 'before func'     func()     print 'after func'     return func def myfunc():     print 'myfunc() called'   myfunc = deco(myfunc)

def deco(func):     print 'before func'     func()     print 'after func'     return func @deco def myfunc():     print 'myfunc() called' myfunc()

def deco(func):     def _deco():         print 'before func'         func()         print 'after func'     return _deco @deco def myfunc():     print 'myfunc() called'   myfunc()

def deco(arg):     def _deco(func):         print arg         def __deco():             print 'before func'             func()             print 'after func'         return __deco     return _deco @deco('deco') def myfunc():     print 'myfunc() called'   myfunc()

def deco(arg):     def _deco(func):         print arg         def __deco(str):             print 'before func'             func(str)             print 'after func'         return __deco     return _deco @deco('deco') def myfunc(str):     print 'myfunc() called ', str   myfunc('hello')

def deco(arg):     def _deco(func):         print arg         def __deco(*args, **kwargs):             print 'before func'             func(*args, **kwargs)             print 'after func'         return __deco     return _deco @deco('deco1') def myfunc1(str):     print 'myfunc1() called ', str @deco('deco2') def myfunc2(str1,str2):     print 'myfunc2() called ', str1, str2   myfunc1('hello')   myfunc2('hello', 'world')

class myDecorator(object):       def __init__(self, fn):         print "inside myDecorator.__init__()"         self.fn = fn       def __call__(self):         self.fn()         print "inside myDecorator.__call__()"   @myDecorator def aFunction():     print "inside aFunction()"   print "Finished decorating aFunction()"   aFunction()

class myDecorator(object):       def __init__(self, str):         print "inside myDecorator.__init__()"         self.str = str         print self.str       def __call__(self, fn):         def wrapped(*args, **kwargs):             fn()             print "inside myDecorator.__call__()"         return wrapped   @myDecorator('this is str') def aFunction():     print "inside aFunction()"   print "Finished decorating aFunction()"   aFunction()

from functools import wraps def memo(fn):     cache = {}     miss = object()          @wraps(fn)     def wrapper(*args):         result = cache.get(args, miss)         if result is miss:             result = fn(*args)             cache[args] = result         return result       return wrapper   @memo def fib(n):     if n < 2:         return n     return fib(n - 1) + fib(n - 2) print fib(10)

class MyApp():     def __init__(self):         self.func_map = {}       def register(self, name):         def func_wrapper(func):             self.func_map[name] = func             return func         return func_wrapper       def call_method(self, name=None):         func = self.func_map.get(name, None)         if func is None:             raise Exception("No function registered against - " + str(name))         return func()   app = MyApp()   @app.register('/') def main_page_func():     return "This is the main page."   @app.register('/next_page') def next_page_func():     return "This is the next page."   print app.call_method('/') print app.call_method('/next_page')

import umysql from functools import wraps   class Configuraion:     def __init__(self, env):         if env == "Prod":             self.host    = "coolshell.cn"             self.port    = 3306             self.db      = "coolshell"             self.user    = "coolshell"             self.passwd  = "fuckgfw"         elif env == "Test":             self.host   = 'localhost'             self.port   = 3300             self.user   = 'coolshell'             self.db     = 'coolshell'             self.passwd = 'fuckgfw'   def mysql(sql):       _conf = Configuraion(env="Prod")       def on_sql_error(err):         print err         sys.exit(-1)       def handle_sql_result(rs):         if rs.rows > 0:             fieldnames = [f[0] for f in rs.fields]             return [dict(zip(fieldnames, r)) for r in rs.rows]         else:             return []       def decorator(fn):         @wraps(fn)         def wrapper(*args, **kwargs):             mysqlconn = umysql.Connection()             mysqlconn.settimeout(5)             mysqlconn.connect(_conf.host, _conf.port, _conf.user, \                               _conf.passwd, _conf.db, True, 'utf8')             try:                 rs = mysqlconn.query(sql, {})                  except umysql.Error as e:                 on_sql_error(e)               data = handle_sql_result(rs)             kwargs["data"] = data             result = fn(*args, **kwargs)             mysqlconn.close()             return result         return wrapper       return decorator     @mysql(sql = "select * from coolshell" ) def get_coolshell(data):     ... ...     ... ..

from threading import Thread from functools import wraps   def async(func):     @wraps(func)     def async_func(*args, **kwargs):         func_hl = Thread(target = func, args = args, kwargs = kwargs)         func_hl.start()         return func_hl       return async_func   if __name__ == '__main__':     from time import sleep       @async     def print_somedata():         print 'starting print_somedata'         sleep(2)         print 'print_somedata: 2 sec passed'         sleep(2)         print 'print_somedata: 2 sec passed'         sleep(2)         print 'finished print_somedata'       def main():         print_somedata()         print 'back in main'         print_somedata()         print 'back in main'       main()