[Pytables-users] Subclassing isDescription subclass

[Swank, C. <Cra...@nr...>]

Hello,
I would like to be able to make a base class that has some columns, and
subclass that base class so I can inherit those columns, for example:

import tables

class A(tables.IsDescription):
    x = tables.Int32Col()

class B(A):
    y = tables.Int32Col()

inFile = tables.openFile('test.h5', mode="w")
group = inFile.createGroup(inFile.root, 'group')
table = inFile.createTable(group, 'table', B, 'a table')

entry = table.row

print  '\n', '*' * 20, 'column names', table.colnames, '*' * 20, '\n'

entry['y'] = 0
entry['x'] = 1

inFile.close()

When I run it I get this:

cswank-09290s:test cswank$ python blah.py

******************** column names ['y'] ********************

Traceback (most recent call last):
  File "blah.py", line 18, in <module>
    entry['x'] = 1
  File "tableExtension.pyx", line 1294, in tableExtension.Row.__setitem__
  File "tableExtension.pyx", line 130, in tableExtension.getNestedFieldCache
  File "utilsExtension.pyx", line 375, in utilsExtension.getNestedField
KeyError: 'no such column: x'
Closing remaining open files: test.h5... Done


Is there a way to inherit columns from a superclass?

Thanks,

Craig