html parser etc help

[Jeremy Yallop]

* Xah Lee
| Thanks Jeremy Yallop for help. Some follow up questions...
| 
| in the following code:
| 
| import os 
| def visit(arg, dirname, fnames): 
|     for file in fnames: 
|         if file.endswith('.html'): 
|             print file 
|             print arg 
| os.path.walk('/export/home/xah/unixnotes/',visit,'---')
| 
| 
| * in the os.path.walk, what's the third argument for?

Here's what the interactive help says:

  >>> import os
  >>> help(os.path.walk)
  Help on function walk in module posixpath:
  
  walk(top, func, arg)
      Directory tree walk with callback function.
      
      [...] No semantics are defined for, or required of, arg, beyond
      that arg is always passed to func.  It can be used, e.g., to
      pass a filename pattern, or a mutable object designed to
      accumulate statistics.  Passing None for arg is common.

| * what if i want to print the full path?

Use os.path.join():

  def visit(arg, dirname, fnames): 
      for file in fnames: 
          if file.endswith('.html'): 
              print os.path.join(dirname, file)

| * what if i want to print a particular type of file, for example only
| directories.

Use os.path.isdir()

| * how to find out about a particular function or method, or what
| modules are available?

In python 2.2, type help() at a (python) prompt, and then 'modules' to
give a list of all modules available on your system.  You can use
help() on a type or function to read its documentation (try
'help(file)' for example).  The full current library reference is at:

   http://www.python.org/doc/current/lib/lib.html

Jeremy.