[GNC] Python script can't read Gnucash files

[John Haiducek]

Thanks Brad and Jim,

You're right, this isn't the latest Fedora release and I'm due for an
upgrade.

But...I saw this evening that a new version of the Gnucash 3.9 package was
available, with the changelog entry "Patch for Python accounting file bug."
I installed the update and my script works again. I did not need to add a
call to `gnucash_session.load()`, though I'll certainly consider trying
that if I encounter a similar problem in the future.

John

On Sat, Nov 30, 2024 at 4:24 PM Jim DeLaHunt <list+gnucash at jdlh.com> wrote:

> John:
> On 2024-11-30 10:55, John Haiducek wrote:
>
> Hi,
>
> A Python script I've been using with Gnucash recently stopped working, and
> is no longer able to read files that could be read previously with the same
> script. The script can open Gnucash XML files, but it doesn't find the
> accounts in them. The script uses the official Gnucash Python API. Both
> Gnucash and the Python bindings were installed using the Fedora package
> manager.
>
> Here's the script:
>
> ```
> from sys import argv
> from gnucash import Session, SessionOpenMode
>
> def account_from_path(top_account, account_path, original_path=None):
>     if original_path==None: original_path = account_path
>     account, account_path = account_path[0], account_path[1:]
>
>     account = top_account.lookup_by_name(account)
>     if account == None:
>         raise Exception(
>             "path " + ':'.join(original_path) + " could not be found")
>
>     if len(account_path) > 0 :
>         return account_from_path(account, account_path, original_path)
>     else:
>         return account
>
> if __name__=='__main__':
>
>     gnucash_file = argv[1]
>
>     gnucash_session=Session(gnucash_file, SessionOpenMode.SESSION_READ_ONLY)
>
>     root_account = gnucash_session.book.get_root_account()
>
>     investments = account_from_path(root_account, ['Assets','Investments'])
> ```
>
> I'm experiencing this with Gnucash 5.9 on Fedora 39, installed using the
> Fedora repositories. I'm not sure how to tell whether this is a Gnucash
> bug, or a packaging error on the Fedora side, or something else. Any
> suggestions for diagnosing or troubleshooting this?
>
> You might need to add `gnucash_session.load()` after your call to
> Session().
>
> For background, see the thread "[GNC] unable to iterate accounts with API
> Python bindings" from October 2024 at
> <https://lists.gnucash.org/pipermail/gnucash-user/2024-October/113845.html>
> <https://lists.gnucash.org/pipermail/gnucash-user/2024-October/113845.html>.
> The crucial insight, from John Ralls:
>
> ...there's been only one change to the bindings since then: I removed a load call from the Session constructor to fix bug 799308. That wasn't exactly the right thing to do, but it's a surmountable problem: Load the session in the script....
>
> I hope that is helpful. Best regards, —Jim DeLaHunt
>
>