Cx_Oracle.NUMBER precision problem ..

Question

Hi All,
i understand that floating point numbers are inherently inaccurate, eg:
0.1 + 0.2 != 0.3
the problem i'm seeing is that:
in sqlplus, a query is returning 0.088 from the Oracle db server,
but cx_Oracle is changing the value to 0.08800000000000001.
at the interpretor, v = 0.088, retains 0.088...
(most likely, the precision is maintained upon definition),
is there a way to set the precision for cx_Oracle.NUMBER ?
thanks very much in advance!
sam

Answer 1

What about using one of these:
# t.py
import cx_Oracle
import decimal
db = cx_Oracle.connect("cj", "cj", "localhost/orcl")
cur = db.cursor()
cur.execute("select volume from goods")
rows = cur.fetchall()
print rows
cur = db.cursor()
cur.execute("select to_char(volume) from goods")
rows = cur.fetchall()
print rows
print float(rows[0][0])
def NumbersAsDecimal(cursor, name, defaultType, size, precision, scale):
    if defaultType == cx_Oracle.NUMBER:
        return cursor.var(str, 100, cursor.arraysize, outconverter = decimal.Decimal)
db.outputtypehandler = NumbersAsDecimal
cur = db.cursor()
cur.execute("select volume from goods")
rows = cur.fetchall()
print rowsOutput is:
$ python t.py
[(0.08800000000000001,)]
[('.088',)]
0.088
[(Decimal('0.088'),)]