Determining when a file has finished copying

[writeson]

Guys,

Thanks for your replies, they are helpful. I should have included in
my initial question that I don't have as much control over the program
that writes (pgm-W) as I'd like. Otherwise, the write to a different
filename and then rename solution would work great. There's no way to
tell from the os.stat() methods to tell when the file is finished
being copied? I ran some test programs, one of which continously
copies big files from one directory to another, and another that
continously does a glob.glob("*.pdf") on those files and looks at the
st_atime and st_mtime parts of the return value of os.stat(filename).
>From that experiment it looks like st_atime and st_mtime equal each
other until the file has finished being copied. Nothing in the
documentation about st_atime or st_mtime leads me to think this is
true, it's just my observations about the two test programs I've
described.

Any thoughts? Thanks!
Doug