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Is gcc's __attribute__((packed)) / #pragma pack unsafe?
In C, the compiler will lay out members of a struct in the order in which they're declared, with possible padding bytes inserted between members, or after the last member, to ensure that each member is aligned properly.
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Get exception description and stack trace which caused an exception, all as a string
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Let's create a decently complicated stacktrace, in order to demonstrate that we get the full stacktrace:
def raise_error():
raise RuntimeError('something bad happened!')
def do_something_that_might_error():
raise_error()
Logging the full stacktrace
A best practic...
Why is iterating through a large Django QuerySet consuming massive amounts of memory?
...etching large items from database.
import gc
# Get the events in reverse order
eids = Event.objects.order_by("-id").values_list("id", flat=True)
for index, eid in enumerate(eids):
event = Event.object.get(id=eid)
# do necessary work with event
if index % 100 == 0:
gc.collect()
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When to use EntityManager.find() vs EntityManager.getReference() with JPA
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So before transaction commit, JPA provider will see stateChanged flag in order to update OR NOT person entity. If no rows is updated after update statement, JPA provider will throw EntityNotFoundException according to JPA specification.
regards,
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How can I recover the return value of a function passed to multiprocessing.Process?
... @dano : I wonder, if we use Queue() object, we can not sure the order when each process return the value. I mean if we need the order in the result, to do the next work. How could we sure where exactly which output is from which process
– Catbuilts
S...
How do I get indices of N maximum values in a NumPy array?
...copy of an array from unconstrained min to unconstrained max in a reversed order)
– FizBack
Oct 19 '16 at 13:51
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Eclipse jump to closing brace
...: as mentioned by Romaintaz below, you can also get Eclipse to auto-select all of the code between two curly braces simply by double-clicking to the immediate right of a opening brace.
share
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impro...
How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?
...og.pg_namespace n ON n.oid = p.pronamespace WHERE n.nspname ~ '^(public)$' ORDER BY 1, 2, 4; Above is the query generated (from \set ECHO_HIDDEN 'on').
– Simon D
Jan 6 '18 at 9:03
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What is `related_name` used for in Django?
...his data
you only can use related name
bom = material.tomaterial.all().order_by('-creation_time')
It is not working otherwise (at least I was not able to skip the usage of related name in case of 2 FK's to the same table.)
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How to create a MySQL hierarchical recursive query
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name,
parent_id
from (select * from products
order by parent_id, id) products_sorted,
(select @pv := '19') initialisation
where find_in_set(parent_id, @pv)
and length(@pv := concat(@pv, ',', id))
Here is a fiddle.
Here, the value specified in @pv := '19...