omarryhan

# Do the first 6 steps only once.
1. pip install --user alembic
2. bash: ``cd {{my_project}} && alembic init alembic``
3. bash: ``text_editor {{my_project}}/alembic.ini``
4. Change: "sqlalchemy.url = postgres://{{username}}:{{password}}@{{address}}/{{db_name}}"
5. bash: ``text_editor {{my_project}}/alembic/env.py``
6. Now, import your metadata/db object from your app.:

    # {{my_project}}/{{my_project_dir}}/app.py
    

Cguilliman

# HANDLER
from django.utils.translation import ugettext_lazy as _

from rest_framework.exceptions import ErrorDetail
from rest_framework.views import exception_handler

non_field_errors = 'non_field_errors'


def set_custome_errors(errors):

adamchainz

# refactor of https://lukeplant.me.uk/blog/posts/double-checked-locking-with-django-orm/
# untested

def double_checked_lock_iterator(queryset):
    for item_pk in queryset.values_list("pk", flat=True):
        with transaction.atomic():
            try:
                yield queryset.select_for_update(skip_locked=True).get(id=item_pk)
            except queryset.model.DoesNotExist:
                pass

spookylukey

class AfterFetchQuerySetMixin:
    """
    QuerySet mixin to enable functions to run immediately
    after records have been fetched from the DB.
    """
    # This is most useful for registering 'prefetch_related' like operations
    # or complex aggregations that need to be run after fetching, but while
    # still allowing chaining of other QuerySet methods.
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

horodchukanton

import logging
from concurrent.futures import ThreadPoolExecutor
from datetime import timedelta, datetime
from typing import Any, Dict


class SimpleStorageEntry:
    _counter: int = 0

    id: int