python binding: getting invoice entry data

[Brian St. Pierre]

I'm trying to use the python bindings to fetch entry (line-item) data
from an invoice.

See http://pastebin.com/fy06CPup for the test GnuCash XML file I'm using.

I expect the script below to print the three line items from the
invoice in that file, but instead it dies with:

% gnucash-env python invoice_read.py test2.gnucash
* 15:07:39  WARN <gnc.backend.dbi> [gnc_module_init_backend_dbi()] No
DBD drivers found
Traceback (most recent call last):
  File "invoice_read.py", line 16, in <module>
    print entry.GetDescription()
  File "/usr/lib/python2.6/dist-packages/gnucash/function_class.py",
line 92, in method_function
    *process_list_convert_to_instance(meth_func_args) )
  File "/usr/lib/python2.6/dist-packages/gnucash/gnucash_core_c.py",
line 3825, in gncEntryGetDescription
    return _gnucash_core_c.gncEntryGetDescription(*args)
TypeError: in method 'gncEntryGetDescription', argument 1 of type
'GncEntry const *'

Other methods on the Entry objects yield similar results. (A similar
approach to the code below with Invoice and Customer objects works
ok.)

Running on Ubuntu Lucid. Tested with 2.4.0-1~getdeb1~lucid from
getdeb.net and from svn with the same results.

Can someone point out what I'm doing wrong?

Thanks.

--
Brian St. Pierre



#!/usr/bin/env python
import os
import sys

from gnucash import Session
from gnucash.gnucash_business import Entry

uri = "xml://{0}".format(os.path.abspath(sys.argv[1]))
ses = Session(uri, is_new=False)
try:
    book = ses.get_book()
    invoice = book.InvoiceLookupByID('0001')
    assert(len(invoice.GetEntries()) == 3)
    for e in invoice.GetEntries():
        entry = Entry(instance=e)
        print entry.GetDescription()
finally:
    ses.end()