I also posted this to SO
https://stackoverflow.com/questions/58600159/search-results-from-a-django-model-method-including-the-results-from-earlier-cal
hope that's ok, let me know if not.
I have a Django Model that tracks email message IDs as the message passes
through different servers. It has a models.ForeignKey field to itself, so
we can chain them together to follow the full path of a message through
many servers.
The model has a 'get_children()' method that recursively looks for all
messages descended from the given message.
class Relay(models.Model):
hostname = models.CharField(max_length=48)
qid = models.CharField(max_length=24)
received_from = models.ForeignKey(
"self",
blank=True,
null=True,
default=None,
on_delete=models.SET_DEFAULT
)
def get_children(self, parent_messages=set()):
for r in Relay.objects.filter(received_from=self):
r.get_children(parent_messages)
parent_messages.add(self)
p = list(parent_messages)
parent_messages = set()
return p
If I run a single query from the Django shell, it works as expected. "Solo"
messages return only themselves. Messages with multiple child/descendant
messages are found as well.
>>> r = Relay.objects.get(qid='xo2')
>>> r.get_children()
[<Relay: server2 foo>, <Relay: server3 bbb>, <Relay: server1 xo2>]
If I kill and restart the shell, the next query works as expected, fetching
a single message
>>> r = Relay.objects.get(qid='singletonMsg')
>>> r.get_children()
[<Relay: server5 singletonMsg>]
But if I run get_children() repeatedly within a single Django shell
session, it always includes the results of the previous get_children()
calls.
>>> r = Relay.objects.get(qid='singletonMsg')
>>> r.get_children()
# expected result
[<Relay: server5 singletonMsg>]
>>>
>>> r = Relay.objects.get(qid='xo2')
>>> r.get_children()
# unexpected result - should not include singletonMsg
[<Relay: server2 foo>, <Relay: server3 bbb>, <Relay: server5
singletonMsg>, <Relay: server1 xo2>]
>>>
>>> r = Relay.objects.get(qid='singletonMsg')
>>> r.get_children()
# unexected result - should just return singletonMsg ??
[<Relay: server2 foo>, <Relay: server3 bbb>, <Relay: server5
singletonMsg>, <Relay: server1 xo2>]
I was originally returning the "parent_messages" set from the function. I
tried
return [m for m in parent_messages]
and the current list() thinking it was a closure issue, but no luck.
I am stumped. Thanks in advance for any advice.
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-users/84bc2c30-9186-4005-b6c3-530896619eb4%40googlegroups.com.
