On Monday, July 13, 2015 at 1:38:44 AM UTC+5:30, Martin Blais wrote:
>
> 2015-07-11
>
> - WARNING: API CHANGES AHEAD. If you wrote plugins, you will need to
> remove
> the 'entry' parameter to constructors of Posting().
>
> I removed the Posting.entry back-reference of Postings to their owning
> Transaction objects. This makes programmatically creating our data
> structures much more straight-forward and avoids us having to run
> pirouettes
> around which object to create first. It also removes all manners of
> "fixing
> up" transactions and removes one ultimatley unnecessary degree of
> freedom
> from plugins outputs: we don't have to check that the plugins generate
> objects with correct back-references. It also makes the documentation
> simpler: I won't have to explain backreferences and how to deal with
> them.
> Finally, it avoids the circular reference which could potentially make
> Python's GC do some work for no other reason.
>
> This happened because it occurred to me that the only really important
> place
> where back-references were used were in the beancount.core.realization
> code,
> and that in the RealAccount objects I could easily replace the Posting
> instances in lists of "postings or entries" into a new tuple object
> "TxnPosting" that contains a reference to the parent transaction and a
> reference to the posting. This voids the need for a back-reference, and
> makes the API really straightforward.
>
Hi Martin,
Quick question: so now, it is best practice to keep track of the
transaction when iterating through postings? In other words:
---------------------
Old code:
---------------
# replace the account on a given posting with a new account
def account_replace(posting, new_account):
# create a new posting with the new account, then remove old and add
new
# from parent transaction
new_posting = posting._replace(account=new_account)
new_posting.entry.postings.remove(posting)
new_posting.entry.postings.append(new_posting)
matches = [p for t in zerosum_txns for p in t.postings if p.account ==
"Expenses:Blah"]
account_replace(matches[0], new_account)
New code:
---------------
def account_replace(txn, posting, new_account):
new_posting = posting._replace(account=new_account)
txn.postings.remove(posting)
txn.postings.append(new_posting)
matches = [(p, t) for t in zerosum_txns for p in t.postings if p.account ==
"Expenses:Blah"]
account_replace(matches[0][1], matches[0][0], new_account)
---------------------
Does this look right, or should I be iterating through transactions in some
other way (using TxnPosting, perhaps)?
Thanks
--
---
You received this message because you are subscribed to the Google Groups
"Ledger" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
