@pitrou
Hmm... the online docs and the contents of the doc directory on the trunk branch say differently:
"""
Resize the stream to the given *size* in bytes (or the current position if *size* is not specified).  The current stream position isn't changed. This resizing can extend or reduce the current file size.  In case of extension, the contents of the new file area depend on the platform (on most systems, additional bytes are zero-filled, on Windows they're undetermined).  The new file size is returned.
"""
Unless you know something else about this, I'm going to assume it's still okay to use.

@r.david.murray
Thanks for your comments -- I'm trying to put together some unit tests and documentation, against the Subversion trunk.

Tom