[Pytables-users] pyTables modifies data

[Jernej M. <jer...@gm...>]

Hi.
pyTables saves wrong data to file. I read the docs, but I don't know what
I'm doing wrong. It's the first time I noticed this kind of behavior. Any
suggestions?

*problem: *
writing items in testL = [12.12, 12.1234567] to table
data in table: col1 = 12.1199998856, col2 = 12.1234569550
expected: col1 = 12.12, col2 = 12.1234567

*script:*
class MyDescrClass(IsDescription):
    eventDate = Float64Col()
    col1 = Float32Col()
    col2 = Float32Col()

newdb = "_misc/db/test.h5"
dbFilters = tables.Filters(complevel=9, complib='blosc', shuffle=1)
h5file = tables.openFile(db, filters=dbFilters, mode="a")

testL = [12.12, 12.1234567]
print("data in list: %.10f, %.10f" % (testL[0], testL[1]))

newh5file = tables.openFile(newdb, filters=dbFilters, mode="a")
newh5file.createTable(newh5file.root, "myTable", MyDescrClass, "someTitle",
filters=dbFilters, expectedrows=1000000000)

testT = newh5file.root.myTable
testT.row["col1"] = testL[0]
testT.row["col2"] = testL[1]
testT.row["eventDate"] = 1311530521.215325
testT.row.append()
testT.flush()

for row in testT:
    print("data in table: col1 = %.10f, col2 = %.10f" % (row["col1"],
row["col2"]))
newh5file.close()

*output:*
data in list: 12.1200000000, 12.1234567000
data in table: col1 = 12.1199998856, col2 = 12.1234569550


tables.print_versions()
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
PyTables version:  2.4.0
HDF5 version:      1.8.4-patch1
NumPy version:     1.6.1
Numexpr version:   1.4.2 (not using Intel's VML/MKL)
Zlib version:      1.2.3.4 (in Python interpreter)
BZIP2 version:     1.0.6 (6-Sept-2010)
Blosc version:     1.1.3 (2010-11-16)
Cython version:    0.15.1
Python version:    2.7.3 (default, Aug  1 2012, 05:14:39)
[GCC 4.6.3]
Platform:          linux2-x86_64
Byte-ordering:     little
Detected cores:    4
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