Last active
July 24, 2019 00:22
-
-
Save kingbuzzman/ac2ada9c27196fc90c1b75f2d01a6271 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/env python | |
# -*- coding:utf-8 -*- | |
# Stolen from: https://mlvin.xyz/django-single-file-project.html | |
import datetime | |
import inspect | |
import os | |
import sys | |
from types import ModuleType | |
import django | |
from django.conf import settings | |
BASE_DIR = os.path.dirname(os.path.abspath(__file__)) | |
# The current name of the file, which will be the name of our app | |
APP_LABEL, _ = os.path.splitext(os.path.basename(os.path.abspath(__file__))) | |
# Migrations folder need to be created, and django needs to be told where it is | |
APP_MIGRATION_MODULE = '%s_migrations' % APP_LABEL | |
APP_MIGRATION_PATH = os.path.join(BASE_DIR, APP_MIGRATION_MODULE) | |
# Create the folder and a __init__.py if they don't exist | |
if not os.path.exists(APP_MIGRATION_PATH): | |
os.makedirs(APP_MIGRATION_PATH) | |
open(os.path.join(APP_MIGRATION_PATH, '__init__.py'), 'w').close() | |
# Hack to trick Django into thinking this file is actually a package | |
sys.modules[APP_LABEL] = sys.modules[__name__] | |
sys.modules[APP_LABEL].__path__ = [os.path.abspath(__file__)] | |
settings.configure( | |
DEBUG=True, | |
ROOT_URLCONF='%s.urls' % APP_LABEL, | |
MIDDLEWARE=(), | |
INSTALLED_APPS=[APP_LABEL], | |
MIGRATION_MODULES={APP_LABEL: APP_MIGRATION_MODULE}, | |
SITE_ID=1, | |
DATABASES={ | |
'default': { | |
'ENGINE': 'django.db.backends.sqlite3', | |
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), | |
} | |
}, | |
LOGGING={ | |
'version': 1, | |
'disable_existing_loggers': False, | |
'formatters': { | |
'simple': { | |
'format': "%(levelname)s %(message)s", | |
}, | |
}, | |
'handlers': { | |
'console': { | |
'level': 'DEBUG', | |
'class': 'logging.StreamHandler', | |
'formatter': 'simple', | |
} | |
}, | |
'loggers': { | |
'django.db.backends': {'handlers': ['console'], 'level': 'DEBUG', 'propagate': False}, | |
'django.db.backends.schema': {'level': 'ERROR'}, # Causes sql logs to duplicate -- really annoying | |
} | |
}, | |
STATIC_URL='/static/' | |
) | |
django.setup() | |
from django.apps import apps # noqa: E402 isort:skip | |
# Setup the AppConfig so we don't have to add the app_label to all our models | |
def get_containing_app_config(module): | |
if module == '__main__': | |
return apps.get_app_config(APP_LABEL) | |
return apps._get_containing_app_config(module) | |
apps._get_containing_app_config = apps.get_containing_app_config | |
apps.get_containing_app_config = get_containing_app_config | |
# Your code below this line | |
# ############################################################################## | |
from django.db import models # noqa: E402 isort:skip | |
from django.test import TestCase # noqa: E402 isort:skip | |
class Worker(models.Model): | |
name = models.CharField(max_length=128) | |
class Job(models.Model): | |
worker = models.ForeignKey(Worker, on_delete=models.PROTECT) | |
type = models.CharField(max_length=64) | |
position = models.CharField(max_length=64) | |
location = models.CharField(max_length=128) | |
start_date = models.DateField() | |
urlpatterns = [] | |
class SimpleTestCase(TestCase): | |
""" | |
Simple test that shows your example running. | |
""" | |
SOLUTION_EXPECTED = [ | |
('A', 'east', datetime.date(2019, 5, 11)), | |
('B', 'west', datetime.date(2019, 1, 1)) | |
] | |
MY_SOLUTION_NUM_QUERIES = 2 | |
HAKEN_NUM_QUERIES = 3 | |
def setUp(self): | |
worker_a = Worker.objects.create(name='A') | |
worker_b = Worker.objects.create(name='B') | |
Job.objects.create(worker=worker_a, location='east', start_date=datetime.date(2018, 1, 21)) | |
Job.objects.create(worker=worker_a, location='south', start_date=datetime.date(2018, 9, 13)) | |
Job.objects.create(worker=worker_a, location='east', start_date=datetime.date(2019, 5, 11)) | |
Job.objects.create(worker=worker_b, location='west', start_date=datetime.date(2019, 1, 1)) | |
def test_my_solution(self): | |
from django.db import models # needs to be here becuase of the hack that is having a single django file # noqa | |
actual = [] | |
expected = self.SOLUTION_EXPECTED | |
with self.assertNumQueries(self.MY_SOLUTION_NUM_QUERIES): | |
subqry = models.Subquery(Job.objects.filter(worker_id=models.OuterRef('worker_id')) | |
.order_by('-start_date').values('id')[:1]) | |
workers = Worker.objects.prefetch_related(models.Prefetch('job_set', | |
queryset=Job.objects.filter(id__in=subqry))) | |
for worker in workers: | |
latest_job = list(worker.job_set.all())[0] | |
actual.append((worker.name, latest_job.location, latest_job.start_date)) | |
self.assertEqual(actual, expected) | |
def test_haken_lid(self): # Håken Lid | |
from django.db import models # needs to be here becuase of the hack that is having a single django file # noqa | |
actual = [] | |
expected = self.SOLUTION_EXPECTED | |
with self.assertNumQueries(self.HAKEN_NUM_QUERIES): | |
for worker in Worker.objects.all(): | |
latest_job = worker.job_set.latest('start_date') | |
actual.append((worker.name, latest_job.location, latest_job.start_date)) | |
self.assertEqual(actual, expected) | |
class ComplexTestCase(SimpleTestCase): | |
""" | |
Shows that if you have more and more workers the other solution will continue to grow, my solution stays the same | |
with the same results | |
""" | |
SOLUTION_EXPECTED = [ | |
('A', 'south', datetime.date(2018, 2, 2)), | |
('B', 'east', datetime.date(2018, 4, 4)), | |
('C', 'north', datetime.date(2018, 6, 6)), | |
('D', 'west', datetime.date(2018, 8, 8)), | |
] | |
MY_SOLUTION_NUM_QUERIES = 2 | |
HAKEN_NUM_QUERIES = 5 | |
def setUp(self): | |
worker_a = Worker.objects.create(name='A') | |
worker_b = Worker.objects.create(name='B') | |
worker_c = Worker.objects.create(name='C') | |
worker_d = Worker.objects.create(name='D') | |
Job.objects.create(worker=worker_a, location='east', start_date=datetime.date(2018, 1, 1)) | |
Job.objects.create(worker=worker_a, location='south', start_date=datetime.date(2018, 2, 2)) | |
Job.objects.create(worker=worker_b, location='north', start_date=datetime.date(2018, 3, 3)) | |
Job.objects.create(worker=worker_b, location='east', start_date=datetime.date(2018, 4, 4)) | |
Job.objects.create(worker=worker_c, location='west', start_date=datetime.date(2018, 5, 5)) | |
Job.objects.create(worker=worker_c, location='north', start_date=datetime.date(2018, 6, 6)) | |
Job.objects.create(worker=worker_d, location='east', start_date=datetime.date(2018, 7, 7)) | |
Job.objects.create(worker=worker_d, location='west', start_date=datetime.date(2018, 8, 8)) | |
class O_N_TestCase(SimpleTestCase): | |
""" | |
Shows that if you have more and more workers the other solution will continue to grow, my solution stays the same | |
with the same results | |
""" | |
SOLUTION_EXPECTED = [ | |
('A', 'north', datetime.date(2018, 1, 1)), | |
('B', 'north', datetime.date(2018, 1, 1)), | |
('C', 'north', datetime.date(2018, 1, 1)), | |
('D', 'north', datetime.date(2018, 1, 1)), | |
('E', 'north', datetime.date(2018, 1, 1)), | |
('F', 'north', datetime.date(2018, 1, 1)), | |
('G', 'north', datetime.date(2018, 1, 1)), | |
('H', 'north', datetime.date(2018, 1, 1)), | |
('I', 'north', datetime.date(2018, 1, 1)), | |
('J', 'north', datetime.date(2018, 1, 1)), | |
('K', 'north', datetime.date(2018, 1, 1)), | |
('L', 'north', datetime.date(2018, 1, 1)), | |
('M', 'north', datetime.date(2018, 1, 1)), | |
('N', 'north', datetime.date(2018, 1, 1)), | |
('O', 'north', datetime.date(2018, 1, 1)), | |
('P', 'north', datetime.date(2018, 1, 1)), | |
('Q', 'north', datetime.date(2018, 1, 1)), | |
('R', 'north', datetime.date(2018, 1, 1)), | |
('S', 'north', datetime.date(2018, 1, 1)), | |
('T', 'north', datetime.date(2018, 1, 1)), | |
('U', 'north', datetime.date(2018, 1, 1)), | |
('V', 'north', datetime.date(2018, 1, 1)), | |
('W', 'north', datetime.date(2018, 1, 1)), | |
('X', 'north', datetime.date(2018, 1, 1)), | |
('Y', 'north', datetime.date(2018, 1, 1)), | |
('Z', 'north', datetime.date(2018, 1, 1)), | |
] | |
MY_SOLUTION_NUM_QUERIES = 2 | |
HAKEN_NUM_QUERIES = 27 | |
def setUp(self): | |
import string | |
self.maxDiff = None | |
for letter in string.ascii_uppercase: | |
worker = Worker.objects.create(name=letter) | |
Job.objects.create(worker=worker, location='north', start_date=datetime.date(2018, 1, 1)) | |
# Your code above this line | |
# ############################################################################## | |
# Used so you can do 'from <name of file>.models import *' | |
models_module = ModuleType('%s.models' % (APP_LABEL)) | |
tests_module = ModuleType('%s.tests' % (APP_LABEL)) | |
urls_module = ModuleType('%s.urls' % (APP_LABEL)) | |
urls_module.urlpatterns = urlpatterns | |
for variable_name, value in list(locals().items()): | |
# We are only interested in models | |
if inspect.isclass(value) and issubclass(value, models.Model): | |
setattr(models_module, variable_name, value) | |
# We are only interested in tests | |
if inspect.isclass(value) and issubclass(value, TestCase): | |
setattr(tests_module, variable_name, value) | |
# Setup the fake modules | |
sys.modules[models_module.__name__] = models_module | |
sys.modules[tests_module.__name__] = tests_module | |
sys.modules[urls_module.__name__] = urls_module | |
sys.modules[APP_LABEL].models = models_module | |
sys.modules[APP_LABEL].tests = tests_module | |
sys.modules[APP_LABEL].urls = urls_module | |
if __name__ == "__main__": | |
# Hack to fix tests | |
argv = [arg for arg in sys.argv if not arg.startswith('-')] | |
if len(argv) == 2 and argv[1] == 'test': | |
sys.argv.append(APP_LABEL) | |
from django.core.management import execute_from_command_line | |
execute_from_command_line(sys.argv) | |
else: | |
from django.core.wsgi import get_wsgi_application | |
get_wsgi_application() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
In order to run the code above run the following:
If you want the REAL copy and paste version:
Answers stackoverflow question: https://stackoverflow.com/questions/57169445/django-reverse-foreign-key/57170596