[Numpy-discussion] Setting custom dtypes and 1.14

Chris Barker chris.barker at noaa.gov
Fri Jan 26 17:48:25 EST 2018


On Fri, Jan 26, 2018 at 2:35 PM, Allan Haldane <allanhaldane at gmail.com>
wrote:

> As I remember, numpy has some fairly convoluted code for array creation
> which tries to make sense of various nested lists/tuples/ndarray
> combinations. It makes a difference for structured arrays and object
> arrays. I don't remember the details right now, but I know in some cases
> the rule is "If it's a Python list, recurse, otherwise assume it is an
> object array".
>

that's at least explainable, and the "try to figure out what the user
means" array cratinon is pretty much an impossible problem, so what we've
got is probably about as good as it can get.

> >     These points make me think that instead of a `.totuple` method, this
> >     might be more suitable as a new function in np.lib.recfunctions.
> >
> > I don't seem to have that module -- and I'm running 1.14.0 -- is this a
> > new idea?
>
> Sorry, I didn't specify it correctly. It is "numpy.lib.recfunctions".
>

thanks -- found it.


> Also, the functions in that module encourage "pandas-like" use of
> structured arrays, but I'm not sure they should be used that way. I've
> been thinking they should be primarily used for binary interfaces
> with/to numpy, eg to talk to C programs or to read complicated binary
> files.
>

that's my use-case. And I agree -- if you really want to do that kind of
thing, pandas is the way to go.

I thought recarrays were pretty cool back in the day, but pandas is a much
better option.

So I pretty much only use structured arrays for data exchange with C
code....

-CHB

-- 

Christopher Barker, Ph.D.
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