[Tutor] Changing filenames

[Michael P. Reilly]

> 
> I'd like to change all the filenames in a directory.  They have a standard
> naming convention, but the important stuff is being used as a file type
> extension.  Does anyone know of a way to append the existing extension to
> the end of the filename and then switch all the extensions to ".this"?
> -- John C.
> 

You might want to clarify what "standard naming convention" is.
Standard for Windows is not a standard for Mac or UNIX.

I assume that you are asking how to append ".this" to the end of all
names of files in a directory.

  >>> import os
  >>> for fname in os.listdir(os.curdir):  # files in current directory
  ...   os.rename(fname, fname + '.this')
  ...
  >>>

This gets you filenames like "spam.txt.this" and "eggs.spam.this".

If you want to do something more complex, for example, changing each
extension to be a part of the base name instead of the extension, e.g.
changing ".txt" to "-txt".  Here you might get instead "spam-txt.this"
and "eggs-spam.this".

  >>> import os
  >>> for fname in os.listdir(os.curdir):
  ...   basename, ext = os.path.splitext(fname)
  ...   newname = basename + '-' + ext[1:] # chop off '.'
  ...   os.rename(fname, newname + '.this')
  ...
  >>>

Most of the tools in the os.path module will help you with what you
need.  <URL: http://www.python.org/doc/current/lib/module-os.path.html>

Enjoy! :)
  -Arcege

-- 
------------------------------------------------------------------------
| Michael P. Reilly, Release Engineer | Email: arcege@shore.net        |
| Salem, Mass. USA  01970             |                                |
------------------------------------------------------------------------