[Pytables-users] In-kernel searches not returning values?

[Giovanni L. C. <glc...@gm...>]

Hi,

I am new to PyTables and I like it very much though there are still some 
problems I am trying to solve. The latest is that I am seeing a strange behavior 
when using in-kernel searches. The seach condition is a simple equality test on 
a single column. Basically, when the column is indexed, in-kernel searches don't 
return the expected result, that is:

In [150]: [ row['visits'] for row in ap.where('rid == 665689') ]
Out[150]: []

In [151]: [ row['visits'] for row in ap if row['rid'] == 665689 ]
Out[151]: [18L]

When I remove the index, it works again:

In [153]: ap.cols.rid.removeIndex()

In [154]: [ row['visits'] for row in ap.where('rid == 665689') ]
Out[154]: [18L]

Am I doing something wrong? This is an excerpt of the contents of the file:

-> % h5ls -ld test.h5|head
AllPages Dataset {529000/Inf}
Data:
(0) {year=2008, month=1, day=1, hour=0, minute=0, epoch=1199145600, rid=665689,
(0) visits=18},
(1) {year=2008, month=1, day=1, hour=0, minute=0, epoch=1199145600, rid=2,
(1) visits=11},
(2) {year=2008, month=1, day=1, hour=0, minute=0, epoch=1199145600, rid=12,
(2) visits=1},
(3) {year=2008, month=1, day=1, hour=0, minute=0, epoch=1199145600, rid=612075,
(3) visits=8},

And this is the table description:

Out[152]:
/AllPages (Table(529000,), shuffle, zlib(5)) ''
description := {
"year": UInt16Col(shape=(), dflt=0, pos=0),
"month": UInt8Col(shape=(), dflt=0, pos=1),
"day": UInt8Col(shape=(), dflt=0, pos=2),
"hour": UInt8Col(shape=(), dflt=0, pos=3),
"minute": UInt8Col(shape=(), dflt=0, pos=4),
"epoch": UInt32Col(shape=(), dflt=0, pos=5),
"rid": UInt32Col(shape=(), dflt=0, pos=6),
"visits": UInt32Col(shape=(), dflt=0, pos=7)}
byteorder := 'little'
chunkshape := (233016,)
autoIndex := True
colindexes := {
"rid": Index(1, light, shuffle, zlib(1)).is_CSI=False}

Thanks!

-- 
Giovanni Luca Ciampaglia

Postdoctoral fellow
Center for Complex Networks and Systems Research
Indiana University

✎ 910 E 10th St ∙ Bloomington ∙ IN 47408
☞ http://cnets.indiana.edu/
✉ gci...@in...