PROGRAMAÇÃO ASSÍNCRONA COMASYNCIO

PythonDay Campina Grande 2017

Allisson Azevedo

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ALLISSON AZEVEDOallissonazevedo.com

youtube.com/user/allissonazevedo

github.com/allisson

twitter.com/allisson

linkedin.com/in/allisson/

allisson.github.io/slides/

allisson@gmail.com

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THE C10K PROBLEMComo lidar com 10k conexões simultâneas

http://www.kegel.com/c10k.html

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CONCORRÊNCIA

Asynchronous I/O

O exemplo do garçom

Não confundir com paralelismo

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PROGRAMAÇÃO SÍNCRONAimport time import requests from github import REPOS, ACCESS_TOKEN

start = time.time() for repo_url in REPOS: response = requests.get(repo_url, params={'access_token': ACCESS_TOKEN}).json() repo_info = { 'name': response['name'], 'full_name': response['full_name'], 'stargazers_count': response['stargazers_count'] } print(repo_info) end = time.time() print('Tempo de execução={:.2f} segundos'.format(end - start))

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PROBLEMAS COM PROGRAMAÇÃOSÍNCRONA

Uma requisição http por vez

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CONCORRÊNCIA USANDO THREADSimport time import threading import queue import requests from github import REPOS, ACCESS_TOKEN

def grab_data_from_queue(): while not q.empty(): repo_url = q.get() response = requests.get(repo_url, params={'access_token' repo_info = { 'name': response['name'], 'full_name': response['full_name'], 'stargazers_count': response['stargazers_count'] }

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PROBLEMAS COM THREADS

Consumo de recursos

Global Interpreter Lock (GIL)

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CONCORRÊNCIA USANDO PROCESSimport time import multiprocessing import requests from github import REPOS, ACCESS_TOKEN

def grab_data_from_queue(): while not q.empty(): repo_url = q.get() response = requests.get(repo_url, params={'access_token' repo_info = { 'name': response['name'], 'full_name': response['full_name'], 'stargazers_count': response['stargazers_count'] } print(repo_info)

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PROBLEMAS COM PROCESSConsumo de recursos

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CONCORRÊNCIA USANDOCONCURRENT.FUTURES

import time from concurrent import futures import requests from github import REPOS, ACCESS_TOKEN

def get_repo_info(repo_url): response = requests.get(repo_url, params={'access_token': ACCESS_TOKEN}).json() repo_info = { 'name': response['name'], 'full_name': response['full_name'], 'stargazers_count': response['stargazers_count'] } print(repo_info)

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PROBLEMAS COMCONCURRENT.FUTURES

ThreadPoolExecutor - usa threads

ProcessPoolExecutor - usa process

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ASYNCHRONOUS I/O COM PYTHONTwisted

Tornado

Eventlet

Gevent

Asyncio

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ASYNCIO

Python 3.4+

Tulip

PEP-3156

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HELLO WORLDimport asyncio

async def hello_world(): print('Hello World!')

loop = asyncio.get_event_loop() loop.run_until_complete(hello_world())

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HELLO WORLD COM TASKSimport asyncio

async def hello_world(name): print('Hello World, {}!'.format(name))

loop = asyncio.get_event_loop() tasks = [] for name in ('fulano', 'cicrano', 'beltrano'): task = asyncio.ensure_future(hello_world(name)) tasks.append(task) loop.run_until_complete(asyncio.wait(tasks))

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CONCORRÊNCIA USANDO ASYNCIOimport time import asyncio import aiohttp from github import REPOS, ACCESS_TOKEN

async def get_repo_info(repo_url): async with aiohttp.ClientSession() as session: async with session.get(repo_url, params={'access_token': ACCESS_TOKEN}) response_data = await response.json() repo_info = { 'name': response_data['name'], 'full_name': response_data['full_name'], 'stargazers_count': response_data['stargazers_count' } print(repo_info)

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AIO LIBShttps://github.com/aio-libs

https://github.com/python/asyncio/wiki/ThirdParty

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PACOimport time import paco import aiohttp from github import REPOS, ACCESS_TOKEN

async def get_repo_info(repo_url): async with aiohttp.ClientSession() as session: async with session.get(repo_url, params={'access_token': ACCESS_TOKEN}) response_data = await response.json() repo_info = { 'name': response_data['name'], 'full_name': response_data['full_name'], 'stargazers_count': response_data['stargazers_count' } print(repo_info)

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AIOHTTPfrom aiohttp import web

async def handle(request): return web.json_response({'message': 'Hello World'})

app = web.Application() app.router.add_get('/', handle) web.run_app(app, host='127.0.0.1', port=8080)

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SANICfrom sanic import Sanic from sanic.response import json

app = Sanic()

@app.route('/') async def test(request): return json({'message': 'Hello World'})

if __name__ == '__main__': app.run(host='127.0.0.1', port=8080)

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AIOREDISimport asyncio import aioredis

loop = asyncio.get_event_loop()

async def main(): redis = await aioredis.create_redis(('localhost', 6379), loop=loop) await redis.set('key', 'hello world') val = await redis.get('key') print(val) redis.close() await redis.wait_closed()

loop.run_until_complete(main())

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AIOMCACHEimport asyncio import aiomcache

loop = asyncio.get_event_loop()

async def main(): mc = aiomcache.Client('127.0.0.1', 11211, loop=loop) await mc.set(b'key', b'hello world') value = await mc.get(b'key') print(value)

loop.run_until_complete(main())

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AIOPGimport asyncio import aiopg from speakers import SPEAKERS

dsn = 'dbname=pythonday user=pythonday password=pythonday host=127.0.0.1'

async def get_pool(): return await aiopg.create_pool(dsn)

async def create_table(): pool = await get_pool() async with pool.acquire() as conn: async with conn.cursor() as cur: await cur.execute('DROP TABLE IF EXISTS speakers')

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AIOPG SQLALCHEMYimport asyncio from aiopg.sa import create_engine import sqlalchemy as sa from speakers import SPEAKERS

metadata = sa.MetaData() speakers_table = sa.Table( 'speakers', metadata, sa.Column('id', sa.Integer, primary_key=True), sa.Column('name', sa.String(255)) )

async def get_engine(): return await create_engine(

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PYTEST-ASYNCIOimport pytest import aiohttp from github import REPOS, ACCESS_TOKEN

async def get_repo_info(repo_url): async with aiohttp.ClientSession() as session: async with session.get(repo_url, params={'access_token': ACCESS_TOKEN}) response_data = await response.json() return { 'name': response_data['name'], 'full_name': response_data['full_name'], 'stargazers_count': response_data['stargazers_count' }

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PERGUNTAS?

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OBRIGADO!

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