Hi everyone,

I've just started using the Pytables2.0 beta, and am very impressed, 
especially with the complex where clauses possible using numexpr.

I have hit one stumbling block in one of my tables, though: selecting on 
a uint8 column. This fails with:
  <type 'exceptions.NotImplementedError'>: variable ``N_ACCT`` refers to 
a 64-bit unsigned integer column,
  not yet supported in conditions, sorry; please use regular Python 
selections
  WARNING: Failure executing file: <RBPresults.py>

Maybe this has been/will be fixed in a newer version of numexpr.

If not, maybe PyTables could pretend that uint8 columns are actually 
8-character strings using a numpy ndarray.view('S8')? These sort in the 
same order (if a bit more slowly). Then everything should be OK 
providing the expressions are simple equality/inequality comparisons.

Then I could alter my code from:
        where_str = '((C_PROD=="%s")&(N_ACCT>=%d)&(N_ACCT<=%d))' % 
(logo, acct_min, acct_max)
to
        where_str = '((C_PROD=="%s")&(N_ACCT>="%d")&(N_ACCT<="%d"))' % 
(logo, acct_min, acct_max) 

Cheers

Stephen


-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Pytables-users mailing list
Pytables-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pytables-users

Reply via email to