[Numpy-discussion] C-API creating new copy of C data

Sebastian Haase haase@msg.ucsf....
Sat Apr 21 09:38:43 CDT 2007

On 4/19/07, Bill Baxter <wbaxter@gmail.com> wrote:
> What's the right way to make a new numpy array that's a copy of some C data?
> There doesn't seem to be any API like PyArray_NewFromDescr that
> /copies/ the void*data pointer for you.  Do I have to write my own
> loops for this?  I can do that, it just seems like it should be a
> library function already, so I'm guessing I'm just overlooking it.
> There seem to be lots of APIs that will wrap pre-existing memory, but
> the ones that allocate for you do not seem to copy.
> A related question -- I'm only trying to copy in order to save myself
> a little hassle regarding how to clean up the allocated chunks.  If
> there's some simple way to trigger a particular deallocation function
> to be called at the right time, then that would be the ideal, really.
> Does that exist?

This is a situation I have been waiting to address for a long time !
In our case the data size is generally considered to be to large to
accept the copy-solution.
A cookbook-wiki entry would be wonderful!
Generally we would have data memory that was allocated via alloc() and
data that was allocated via new[] -- so two different deallocation
functions (free()  and delete[], respectively) would be required for
this to be trigged, once the reference counter goes back to zero.

Sebastian Haase

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