2011/12/7 Francesc Alted <fal...@pytables.org>
> What you are saying is correct, except that the 'guilty' of dropping the
> trailing null characters is NumPy, not HDF5. Look at this:
>
> In [27]: import numpy as np
>
> In [28]: np.array(["aaa"])
> Out[28]:
> array(['aaa'],
> dtype='|S3')
>
> In [29]: np.array(["aaa\x00\x00"])
> Out[29]:
> array(['aaa'],
> dtype='|S5')
>
> Of course, this behaviour for NumPy was discussed long time ago during its
> introduction (around NumPy 1.0 or so, back in 2006), and people (specially
> Travis) found this to be the most convenient for the majority of usages.
> If you are interested in getting the trailing bytes, you can always do:
>
> In [53]: a = np.array(["aaa\x00\x00"])
>
> In [54]: a[0]
> Out[54]: 'aaa'
>
> In [55]: "".join([chr(i) for i in a.view('b')])
> Out[55]: 'aaa\x00\x00'
>
Hmm, in this case the element to convert is a np.string_ and not a ndarray,
but the solution to get the trailing nulls is even easier:
In [70]: a = np.string_('aaa\x00\x00')
In [71]: a
Out[71]: 'aaa'
In [72]: a.data[:]
Out[72]: 'aaa\x00\x00'
--
Francesc Alted
------------------------------------------------------------------------------
Cloud Services Checklist: Pricing and Packaging Optimization
This white paper is intended to serve as a reference, checklist and point of
discussion for anyone considering optimizing the pricing and packaging model
of a cloud services business. Read Now!
http://www.accelacomm.com/jaw/sfnl/114/51491232/
_______________________________________________
Pytables-users mailing list
Pytables-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pytables-users
