Open or not open, that is the stupid question.

#!/usr/bin/env python class Singleton(object): _instance = None def __new__(cls, *args, **kwargs): if not cls._instance: cls._instance = super(Singleton, cls).__new__(cls, *args, **kwargs) return cls._instance print me print you print me == you print id(me) == id(you) $ ./testSingleton.py True True $ You could also use metaclass to implement it. #!/usr/bin/env python class Singleton(type): def __init__(self, *args, **kwargs): super(Singleton, self).__init__(*args, **kwargs) self.__instance = None def __call__(self, *args, **kwargs): if self.__instance is None: self.__instance = super(Singleton, self).__call__(*args, **kwargs) return self.__instance class s(object): __metaclass__ = Singleton def __init__(self, size): self.__size = size def getSize(self): return self.__size class n(object): def __init__(self, size): self.__size = size def ...

If you want to evaluate the string you could create a function like below. #!/bin/env python def toBoolean(str): return if str in ['True', '1'] print toBoolean('True') print toBoolean('False') But you could have an easier way to implement with native module called "ast.literal_eval()" e.g. >>> import ast >>> help(ast.literal_eval) Help on function literal_eval in module ast: literal_eval(node_or_string) Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None. >>> ast.literal_eval('False') False >>> ast.literal_eval('True') True >>> ast.literal_eval('1') 1 >>> ast.literal_eval('0') 0 Wish this helps. regards, Stanley Huang

If you need to setup the vpn on Ubuntu, you could refer to the following 2 links: http://mad-scientist.us/juniper.html http://holyarmy.org/2009/06/vpn-on-ubuntu-linux-with-juniper-network-connect/ Wish this helps. regards, Stanley Huang

pip is a tool for installing and managing Python packages, you could find more info here Wish this helps. regards, Stanley Huang

you can check if MySQL data streams are encrypted or not by the following command: # tcpdump -l -i eth0 -w - src or dst port 3306 | strings Wish this helps. regards, Stanley Huang

The more info, please click here The Chinese resource from OpenFoundry, click here . Wish this helps. regards, Stanley Huang

Slides from Devoxx talk on Language / Library / VM Co-Evolution, more info, please click here . Wish this helps. regards, Stanley Huang