[Numpy-discussion] load from text files Pull Request Review

Pauli Virtanen pav@iki...
Thu Sep 8 02:43:48 CDT 2011


Wed, 07 Sep 2011 12:52:44 -0700, Chris.Barker wrote:
[clip]
> In [9]: temp['x'] = 3
> 
> In [10]: temp['y'] = 4
> 
> In [11]: temp['z'] = 5
[clip]
> maybe it wouldn't be any faster, but with re-using temp, and one less
> list-tuple conversion, and fewer python type to numpy type conversions,
> maybe it would.

Structured array assignments have plenty of overhead in Numpy, so it
could be slower, too:

x = np.array((1,2), dtype=[('a', int), ('b', float)])
x2 = [1,2,3]

%timeit x['a'] = 9
100000 loops, best of 3: 2.83 us per loop

%timeit x2[0] = 9
1000000 loops, best of 3: 368 ns per loop



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