os.path.getsize() on Windows

Sean DiZazzo half.italian at gmail.com
Tue Mar 18 23:27:27 CET 2008

On Mar 18, 2:27 pm, Duncan Booth <duncan.bo... at invalid.invalid> wrote:
> Sean DiZazzo <half.ital... at gmail.com> wrote:
> > On windows, this returns the size of the file as it _will be_, not the
> > size that it currently is.  Is this a feature?  What is the proper way
> > to get the current size of the file?  I noticed
> > win32File.GetFileSize()  Does that behave the way I expect?
> > PS.  I also tried os.stat()[6]
> I think all of those will return the current size of the file, but that may
> be the same as the final size: just because the data hasn't been copied
> doesn't mean the file space hasn't been allocated. You don't say how you
> are copying the file, but I seem to remember that Windows copy command pre-
> allocates the file at its final size (so as to reduce fragmentation) and
> then just copies the data after that.
> If you need to make sure you don't access a file until the copy has
> finished then get hwatever is doing the copy to copy it to a temporary
> filename in the same folder and rename it when complete. Then you just have
> to check for existence of the target file.

Hmmm... The file could be copied in by several different sources of
which I have no control.  I can't use your technique in my situation.
I also tried getting md5 hashes with some time in between on advice,
but the file is not opened for reading until the copy completes so I
can't get the hashes.

Any other ideas?

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