This document provides information about Xima and his 5 years of experience in the Python community. It then summarizes some of Xima's work, including Django and Javascript projects on GitHub. The remainder of the document discusses Celery, a Python asynchronous task queue/job queue, including examples of using Celery tasks, chains, groups, signatures, and custom task classes.

2. ● Xima (Filipe Ximenes)
○ Recife
○ 5 anos na comunidade
Python
○ Django
○ Javascript
○ APIs
○ Vinta

4. Django React boilerplate
https://github.com/vintasoftware/django-react-boilerplate
Django Role Permissions
https://github.com/vintasoftware/django-role-permissions
Tapioca
https://github.com/vintasoftware/tapioca-wrapper

6. ●
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12. ?

20. from celery import Celery
app = Celery(...)
@app.task
def soma(a, b):
return a + b
resultado = soma.delay(4, 5).get()
print(resultado) # 9

21. @app.task
def atualizar_participantes(id_evento, n):
e = Eventos.objects.get(id=id_evento)
e.numero_de_participantes = n
e.save()
e = Eventos.objects.get(nome='PySE')
atualizar_participantes.delay(e.id, 9001)

23. resultado = soma.delay(4, 5).get()
?

25. @app.task
def soma(a, b):
return a + b
@app.task
def soma_todos(*args):
resultado = 0
for i in args:
resultado = soma.delay(resultado, i).get()
return resultado
soma_todos.delay(1, 2, 3, 4)

27. soma.apply_async(args=None, kwargs=None,
countdown=0, eta=None,
expires=None, **options)

28. r = soma.apply_async((1, 2), link=soma.s(3))
r.get() # 3
r.children[0].result # 6

29. from celery import chain
c = chain(soma.s(1, 2), soma.s(3), soma.s(4), soma.s(5))
r = c().get() # 15
=
c = soma.s(1, 2) | soma.s(3) | soma.s(4) | soma.s(5)
r = c().get() # 15

30. from celery.schedules import crontab
app.conf.beat_schedule = {
'soma-segunda-de-manhã': {
'task': 'tasks.soma',
'schedule': crontab(hour=7, minute=30,
day_of_week=1),
'args': (1, 2),
},
}

34. GET /eventos/12/ POST /eventos/
{
"nome": "Python Sudeste"
}
DELETE /eventos/12/PUT /eventos/12/
{
"nome": "Python Sudeste"
}

35. GET /eventos/12/ POST /eventos/
{
"nome": "Python Sudeste"
}
DELETE /eventos/12/PUT /eventos/12/
{
"nome": "Python Sudeste"
}

37. @app.task
def atualiza_dados():
user.status = 'atualizado'
user.save()
r = requisição_pro_facebook()
user.name = r.name
user.save()
@app.task
def newsletter_mensal():
r = requisição_pro_facebook()
if r.status != 200:
return
user.name = r.name
user.status = 'atualizado'
user.save()
vs.

38. @app.task
def newsletter_mensal():
usuarios = todos_os_usuarios()
for u in usuarios:
send(email, 'newsletter')
@app.task
def enviar_newsletter(email):
send(email, 'newsletter')
@app.task
def newsletter_mensal():
usuarios = todos_os_usuarios()
for u in usuarios:
enviar_newsletter.delay(u.email)
vs.

39. from tapioca.exceptions import TapiocaException
from tapioca_facebook import Facebook
@app.task(bind=True, retry_limit=4
default_retry_delay=2)
def likes_do_facebook(self):
api = Facebook(access_token=ACCESS_TOKEN)
try:
api.user_likes(id='me').get()
except TapiocaException as e:
self.retry(exc=e)

40. def backoff_exponencial(task_self):
minutos = task_self.default_retry_delay / 60
rand = random.uniform(minutos, minutos * 1.3)
return int(rand ** task_self.request.retries) * 60
self.retry(exc=e,
countdown=backoff_exponencial(self))

41. from celery.exceptions import SoftTimeLimitExceeded
@app.task(task_soft_time_limit=30)
def mytask():
try:
tarefa_possivelmente_longa()
except SoftTimeLimitExceeded:
recuperar()

44. from celery.utils.log import get_task_logger
logger = get_task_logger(__name__)
@app.task
def soma(a, b):
logger.info('Soma {0} + {1}'.format(a, b))
return a + b

48. class Task(object):
# ...
def apply_assync():
# ...
if app.conf.task_always_eager:
return self.apply(...)
# ...
# ...

49. from celery.contrib import rdb
@app.task
def soma_debug(a, b):
rdb.set_trace()
return a + b

51. Licenças:
http://www.flaticon.com/authors/madebyoliver

53. app.conf.task_routes = {
'app.tasks.somar': {'queue': 'somar'},
'app.tasks.subtrair': {'queue': 'subtrair'}
}
$ celery -A proj worker -Q somar, celery
$ celery -A proj worker -Q subtrair
somar.apply_async((1, 2), queue='subtrair')

55. from celery import signature
signature('tasks.add', args=(2, 2), countdown=10)
add.signature((2, 2), countdown=10)
add.s(2, 2)
add.s(2, 2)()
add.delay(2, 2)
add.signature((2, 2), countdown=1).apply_async()
partial = add.s(2)
partial.delay(4)

56. c = chain(add.s(4, 4), mul.s(8), mul.s(10))
res = c().get() # 640
g = group(add.s(2, 2), add.s(4, 4))
res = g().get() # [4, 8]
callback = tsum.s()
header = [add.s(i, i) for i in range(100)]
result = chord(header)(callback)
result.get() # 9900

57. x = xsum.map([range(10), range(100)]).delay()
x.get() # [45, 4950]
p = zip(range(10), range(10))
p # [(0, 0), (1, 1), (2, 2), ...]
s = add.starmap(p).delay()
s.get() # [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
p2 = zip(range(100), range(100))
c = add.chunks(p2, 10)
c().get()
# [[0, 2, 4, 6, 8, 10, 12, 14, 16, 18],
# [20, 22, 24, 26, 28, 30, 32, 34, 36, 38],
# ...

59. from celery import Task
class CustomTask(Task):
def after_return(self, status, retval, task_id,
args, kwargs, einfo):
# ...
def on_failure(self, exc, task_id, args, kwargs,
einfo):
# ...
def on_retry(self, exc, task_id, args, kwargs, einfo):
# ...
def on_success(self, retval, task_id, args, kwargs):
# ...
@app.task(base=CustomTask)
def my_task():
# ...