[SciPy-user] scipy.io.numpyio fwrite - appending or updating an array
Thu Jul 31 17:12:17 CDT 2008
I have an existing binary file containing numpy array data. It has been
created using open,fwrite & close and I can read the data using fread.
I want to be able to either append a new array to the end of the file or
update an existing array within the file.
I've tried opening the file with a mode of either 'ab+' or 'wb+' and
then writing the data using something like....
fd = open(vfname, 'ab+')
fwrite(fd, self.yarray.size, self.yarray,'f')
When I use a mode of 'ab+' it looks like the data has been written to
the file ok (no errors reported) but when I read it back I get my
When I use 'wb+' then my updated data gets written and read back ok. But
when I reload the file, everything apart from my updated data (i.e.
everything before it in the file) is now zero.
The '+' in the mode seems to make no difference.
What am I doing wrong?
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