Python get_BoundingBox returns null

[HalfBaked]

The Transaction Manager is sort of a layer over the revit transactions. Here´s a few more words about it that explain it better than I can:

TransactionManager vs Transaction

The transaction manager is just a layer around the regular revit transactions that manages them for you. It’s preferable to use it instead of regular transactions because that way, if your script crashes before a transaction can be committed, the manager will make sure to finalize everything and do all the necessary cleanup. Otherwise you’ll end up with a stray open transaction, at least until revit’s built-in utilities can clean it up. If you need to do any rollbacks, you can always open a sub…

I guess in this example you could have used TransactionManager.ForceCloseTransaction() instead ot tran.commit(), but personally i never think about it