[Numpy-discussion] Re: Bytes Object and Metadata

Colin J. Williams cjw at sympatico.ca
Fri Apr 1 04:57:57 EST 2005


David M. Cooke wrote:

>Francesc Altet <faltet at carabos.com> writes:
>
>  
>
>>A Dimarts 29 Març 2005 01:59, Travis Oliphant va escriure:
>>    
>>
>>>My proposal:
>>>
>>>__array_data__  (optional object that exposes the PyBuffer protocol or a
>>>sequence object, if not present, the object itself is used).
>>>__array_shape__ (required tuple of int/longs that gives the shape of the
>>>array)
>>>__array_strides__ (optional provides how to step through the memory in
>>>bytes (or bits if a bit-array), default is C-contiguous)
>>>__array_typestr__ (optional struct-like string showing the type ---
>>>optional endianness indicater + Numeric3 typechars, default is 'V')
>>>__array_itemsize__ (required if above is 'S', 'U', or 'V')
>>>__array_offset__ (optional offset to start of buffer, defaults to 0)
>>>      
>>>
>>Considering that heterogenous data is to be suported as well, and
>>there is some tradition of assigning names to the different fields, I
>>wonder if it would not be good to add something like:
>>
>>__array_names__ (optional comma-separated names for record fields)
>>    
>>
>
>A sequence (list or tuple) of strings would be preferable. That
>removes all worrying about using commas in the names.
>
>  
>
As I understand it, record arrays can be heterogenous.  If so, wouldn't 
it make sense for this to be a sequence of tuples?

For example:  [('Name', charStringType), ('Age', _nt.Int8), ...]
 Where _nt is defined by something like:
import numarray.numerictypes as _nt

Colin W.




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