On Jun 11, 12:42 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
> On Jun 11, 9:17 am, Sean Davis <[EMAIL PROTECTED]> wrote:
>
>
>
> > I have a set of numpy arrays which I would like to save to a gzip
> > file. Here is an example without gzip:
>
> > b=numpy.ones(1000000,dtype=numpy.uint8)
> > a=numpy.zeros(1000000,dtype=numpy.uint8)
> > fd = file('test.dat','wb')
> > a.tofile(fd)
> > b.tofile(fd)
> > fd.close()
>
> > This works fine. However, this does not:
>
> > fd = gzip.open('test.dat','wb')
> > a.tofile(fd)
>
> > Traceback (most recent call last):
> > File "<stdin>", line 1, in <module>
> > IOError: first argument must be a string or open file
>
> > In the bigger picture, I want to be able to write multiple numpy
> > arrays with some metadata to a binary file for very fast reading, and
> > these arrays are pretty compressible (strings of small integers), so I
> > can probably benefit in speed and file size by gzipping.
>
> > Thanks,
> > Sean
>
> Use
> fd.write(a)
That seems to work fine. Just to add to the answer a bit, one can
then use:
b=numpy.frombuffer(fd.read(),dtype=numpy.uint8)
to get the array back as a numpy uint8 array.
Thanks for the help.
Sean
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