fromfile error on windows, not mac

Tommy Nordgren tommy.nordgren at
Wed Jul 23 15:25:52 CEST 2008

One question : Did you remember to open the file in binary mode?
This MUST be done on windows.
On 22 jul 2008, at 06.36, jadamwil wrote:

> Hello,
> I am using the numpy fromfile function to read binary data from a file
> on disk. The problem is that the program runs fine on a Mac, but gives
> an error or warning on windows when trying to read the data. I use it
> like this:
> Signal = zeros((N, 16), dtype=float32)
> for sample in range(0, N):
>  # this function gets the next position in the file to seek to
>  s = getFilePos(sample)
>  # go to the correct location in the file; this IS checked to make
> sure it is within the file
>  # read the 16 float32 values from the file
>  D = fromfile(mFile, dtype=numpy.float32, 16)
>  # save D in Signal
>  Signal[sample, :] = D
> This will fail when sample is ~4. If I change the range to (5,N),
> skipping the "bad" file location, it will run fine for a few samples,
> and then give another error. The message it gives is:
> "16 items requested but only 7 read"
> So D is a 7x1 vector, and the program dies when it tries to assign D
> to the slice of Signal ("ValueError: shape mismatch: objects cannot be
> broadcast to a single shape").
> On windows, the Python version is 2.5.2, and the most recent numpy and
> scipy are being used as well. I tried using Enthought, but it gave
> this error as well, in addition to a c runtime error whenever I
> imported scipy (which is another post topic...).
> Any ideas on what might be causing this? Is there a way to debug the
> fromfile function? And, remember, this works perfectly on a Mac. Would
> compiling everything (python, scipy, numpy) potentially solve this?
> Thanks!
> --

Skinheads are so tired of immigration, that they are going to move to  
a country that don't accept immigrants!
Tommy Nordgren
tommy.nordgren at

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