將開發過程常用的內容收藏起來，如下代碼段是關於python 讀取系統環境變量的代碼，應該是對碼農們有些用處。
#!/usr/bin/env python
#
# [SNIPPET_NAME: Read an environmental variable]
# [SNIPPET_CATEGORIES: os]
# [SNIPPET_DESCRIPTION: Read and print a given environmental variable]
# [SNIPPET_AUTHOR: Jono Bacon <jono@ubuntu.com>]
# [SNIPPET_LICENSE: GPL]
import os
# display the USERNAME environmental variable
print os.getenv('USERNAME')