Common tasks in Python

Common tasks including:

1. Traversing file system - os.listdir(dir)
2. Getting file path name - 
• os.path.join(dir, filename): return a path that puts dir and filename together
• os.path.abspath(path): return the absolute path name of path
3. Test file/directory existence - os.path.exists(path)
4. Create directories - os.mkdir(dir_path)
5. High level file operations - shutil module ; in particular file copying and removal
6. Running other commands from within python program - commands module
• commands.getstatusoutput(cmd) : return a tuple (status, output)
• commands.getoutput(cmd)
7. Downloading a web page from an url to a local file - urllib module:
• urllib.retrieve(url, local_dst_path)
  

Reference at:
http://docs.python.org/library/commands.html
http://docs.python.org/library/shutil.html
http://code.google.com/edu/languages/google-python-class/utilities.html
http://docs.python.org/library/urllib.html