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Python高性能编程

news 2025/7/6 14:21:31

一、进程池和线程池

1.串行

import time

import requests

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

start_time = time.time()

for url in url_lists:

response = requests.get(url)

print(response.text)

print("Runtime: {}".format(time.time()-start_time))

# Runtime: 1.95

2.多进程

import time

import requests

from multiprocessing import Process

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

print(response.text)

if __name__ == '__main__':

p_list = []

start_time = time.time()

for url in url_lists:

p = Process(target=task, args=(url,))

p_list.append(p)

p.start()

for p in p_list:

p.join()

print("Runtime: {}".format(time.time() - start_time))

# Runtime: 1.91

3.进程池（1）

import time

import requests

from concurrent.futures import ProcessPoolExecutor

"""

Py2里没有线程池但是有进程池

Py3里有线程池有进程池

"""

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

print(response.content)

if __name__ == '__main__':

start_time = time.time()

pool = ProcessPoolExecutor(10)

for url in url_lists:

pool.submit(task,url)

pool.shutdown(wait=True)

print("Runtime: {}".format(time.time() - start_time))

# Runtime: 2.00

# 进程池 + 回调函数

import time

import requests

from concurrent.futures import ProcessPoolExecutor

"""

Py2里没有线程池但是有进程池

Py3里有线程池有进程池

"""

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

return response.content

def callback(future):

print(future.result())

if __name__ == '__main__':

start_time = time.time()

pool = ProcessPoolExecutor(10)

for url in url_lists:

v = pool.submit(task,url)

v.add_done_callback(callback)

pool.shutdown(wait=True)

print("Runtime: {}".format(time.time() - start_time))

3.进程池（2）

import time

import requests

from multiprocessing import Pool

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

return response.content

def callBackFunc(content):

print(content)

if __name__ == '__main__':

start_time = time.time()

pool = Pool(10)

for url in url_lists:

pool.apply_async(func=task,args=(url,),callback=callBackFunc)

pool.close()

pool.join()

print("Runtime: {}".format(time.time() - start_time))

# Runtime: 1.96

2019-03-06 補充

# Parallel 底层調用的是 multiprocessing

import time

from joblib import Parallel, delayed

def func(idx):

print(idx)

time.sleep(1)

return {'idx':idx}

start_ts = time.time()

results = Parallel(-1)(

delayed(func)(x) for x in range(4)

)

print(results)

print('Runtime : {}'.format(time.time()-start_ts))

4.多线程

import time

import requests

from threading import Thread

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

print(response.text)

if __name__ == '__main__':

t_list = []

start_time = time.time()

for url in url_lists:

t = Thread(target=task, args=(url,))

t_list.append(t)

t.start()

for t in t_list:

t.join()

print("Runtime: {}".format(time.time() - start_time))

# Runtime: 0.49

5.线程池

import time

import requests

from concurrent.futures import ThreadPoolExecutor

"""

Py2里没有线程池但是有进程池

Py3里有线程池有进程池

"""

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

print(response.content)

if __name__ == '__main__':

start_time = time.time()

pool = ThreadPoolExecutor(10)

for url in url_lists:

pool.submit(task,url)

pool.shutdown(wait=True)

print("Runtime: {}".format(time.time() - start_time))

# Runtime: 0.51

# 线程池 + 回调函数

import time

import requests

from concurrent.futures import ThreadPoolExecutor

"""

Py2里没有线程池但是有进程池

Py3里有线程池有进程池

"""

url_lists = [

'http://www.baidu.com',

'http://fanyi.baidu.com',

'http://map.baidu.com',

'http://music.baidu.com/',

'http://tieba.baidu.com',

'http://v.baidu.com',

'http://image.baidu.com',

'http://zhidao.baidu.com',

'http://news.baidu.com',

'http://xueshu.baidu.com']

def task(url):

response = requests.get(url)

return response.content

def callback(future):

print(future.result())

if __name__ == '__main__':

start_time = time.time()

pool = ThreadPoolExecutor(10)

for url in url_lists:

v = pool.submit(task,url)

v.add_done_callback(callback)

pool.shutdown(wait=True)

print("Runtime: {}".format(time.time() - start_time))

二、异步非阻塞

"""

异步非阻塞/异步IO

非阻塞: 不等待

异步: 回调函数

本质：一个线程完成并发操作（前提是执行过程中一定得有IO，这样才能让线程空闲出来去执行下一个任务）

"""

1.asyncio示例1

import asyncio

@asyncio.coroutine

def func1():

print('before...func1......')

yield from asyncio.sleep(2)

print('end...func1......')

@asyncio.coroutine

def func2():

print('before...func2......')

yield from asyncio.sleep(1)

print('end...func2......')

@asyncio.coroutine

def func3():

print('before...func3......')

yield from asyncio.sleep(3)

print('end...func3......')

tasks = [func1(), func2(), func3()]

loop = asyncio.get_event_loop()

loop.run_until_complete(asyncio.gather(*tasks))

loop.close()

### 结果 ###

before...func3......

before...func2......

before...func1......

end...func2......

end...func1......

end...func3......

2.asyncio示例2

####################################################################################

# async/await 是 python3.5中新加入的特性，将异步从原来的yield 写法中解放出来，变得更加直观；

# async 写在def前，替代了装饰器@asyncio.coroutine；await 替换了yield from；

####################################################################################

import asyncio

async def func1():

print('before...func1......')

await asyncio.sleep(2)

print('end...func1......')

async def func2():

print('before...func2......')

await asyncio.sleep(1)

print('end...func2......')

async def func3():

print('before...func3......')

await asyncio.sleep(3)

print('end...func3......')

tasks = [func1(), func2(), func3()]

loop = asyncio.get_event_loop()

loop.run_until_complete(asyncio.gather(*tasks))

loop.close()

3.asyncio示例3

import asyncio

@asyncio.coroutine

def fetch_async(host, url='/'):

print(host, url)

reader, writer = yield from asyncio.open_connection(host, 80)

request_header_content = """GET %s HTTP/1.0\r\nHost: %s\r\n\r\n""" % (url, host,)

request_header_content = bytes(request_header_content, encoding='utf-8')

writer.write(request_header_content)

yield from writer.drain()

text = yield from reader.read()

print(host, url, text)

writer.close()

task_list = [

fetch_async('www.cnblogs.com', '/standby/'),

fetch_async('www.cnblogs.com', '/standby/p/7739797.html'),

fetch_async('www.cnblogs.com', '/wupeiqi/articles/6229292.html')

]

loop = asyncio.get_event_loop()

results = loop.run_until_complete(asyncio.gather(*task_list))

loop.close()

4.asyncio+aiohttp示例1

import asyncio

import aiohttp

import async_timeout

async def fetch(session, url):

with async_timeout.timeout(10):

async with session.get(url) as response:

return await response.text()

async def fetch_async(url):

async with aiohttp.ClientSession() as session:

html = await fetch(session, url)

print(html)

tasks = [

fetch_async('https://api.github.com/events'),

fetch_async('http://aiohttp.readthedocs.io/en/stable/'),

fetch_async('http://aiohttp.readthedocs.io/en/stable/client.html')]

event_loop = asyncio.get_event_loop()

results = event_loop.run_until_complete(asyncio.gather(*tasks))

event_loop.close()

或者

import asyncio

import aiohttp

import async_timeout

async def fetch_async(url):

async with aiohttp.ClientSession() as session:

with async_timeout.timeout(10):

async with session.get(url) as resp:

print(resp.status)

print(await resp.text())

tasks = [

fetch_async('https://api.github.com/events'),

fetch_async('http://aiohttp.readthedocs.io/en/stable/'),

fetch_async('http://aiohttp.readthedocs.io/en/stable/client.html')]

event_loop = asyncio.get_event_loop()

results = event_loop.run_until_complete(asyncio.gather(*tasks))

event_loop.close()

5.asyncio+requests示例

import asyncio

import requests

@asyncio.coroutine

def fetch_async(func, *args):

loop = asyncio.get_event_loop()

future = loop.run_in_executor(None, func, *args)

response = yield from future

print(response.url, response.content)

tasks = [

fetch_async(requests.get, 'http://aiohttp.readthedocs.io/en/stable/'),

fetch_async(requests.get, 'https://api.github.com/events')

]

loop = asyncio.get_event_loop()

results = loop.run_until_complete(asyncio.gather(*tasks))

loop.close()

补充：

有时候会遇到 RuntimeError: Event loop is closed 这个错误

参考：https://stackoverflow.com/questions/45600579/asyncio-event-loop-is-closed

在 fetch_async 函数里添加一下语句即可

asyncio.set_event_loop(asyncio.new_event_loop())

6.gevent+requests示例

import gevent

import requests

from gevent import monkey

from gevent.pool import Pool

monkey.patch_all()

def fetch_async(method, url, req_kwargs):

print(method, url, req_kwargs)

response = requests.request(method=method, url=url, **req_kwargs)

print(response.url, response.content)

# ##### 发送请求 #####

# gevent.joinall([

# gevent.spawn(fetch_async, method='get', url='https://www.python.org/', req_kwargs={}),

# gevent.spawn(fetch_async, method='get', url='https://www.yahoo.com/', req_kwargs={}),

# gevent.spawn(fetch_async, method='get', url='https://github.com/', req_kwargs={}),

# gevent.spawn(fetch_async, method='get', url='https://api.github.com/events', req_kwargs={}),

# ])

# ##### 发送请求（协程池控制最大协程数量） #####

# pool = Pool(None)

pool = Pool(3)

gevent.joinall([

pool.spawn(fetch_async, method='get', url='https://www.python.org/', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.yahoo.com/', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.github.com/', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://api.github.com/events', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.baidu.com', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.ibm.com', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.intel.com', req_kwargs={}),

pool.spawn(fetch_async, method='get', url='https://www.iqiyi.com', req_kwargs={}),

])

使用gevent协程并获取返回值示例：

def get_single_chart_data_flux(single_data_param):

import gevent

from gevent import monkey

from gevent.pool import Pool as gPool

monkey.patch_socket()

ip,port,timestamp,time_length,type_name,subtype_name,filter_str_list,appid,legend = single_data_param

ModelClass = get_model_class(type_name)

func = apps.get_app_config('serverdata').service.get_single_chart_data

pool = gPool(len(filter_str_list))

func_li = []

for filter_str in filter_str_list:

func_li.append(pool.spawn(func,ModelClass,ip,port,timestamp,time_length,subtype_name,filter_str,appid,legend))

ret_li = gevent.joinall(func_li)

# view_logger.debug(ret_li[0].get('value'))

result_li = [{'filter_con':item.get('value')[2], 'value':item.get('value')[1], 'legend':item.get('value')[3]} for item in ret_li]

return result_li

7.Twisted示例

from twisted.web.client import getPage, defer

from twisted.internet import reactor

def all_done(arg):

reactor.stop()

def callback(contents,url):

print(url,contents)

deferred_list = []

url_list = [

'http://www.bing.com',

'http://www.baidu.com',

'https://www.python.org',

'https://www.yahoo.com',

'https://www.github.com'

]

start_time = time.time()

for url in url_list:

deferred = getPage(bytes(url, encoding='utf8'))

deferred.addCallback(callback,url)

deferred_list.append(deferred)

dlist = defer.DeferredList(deferred_list)

dlist.addBoth(all_done)

reactor.run()

8.Tornado示例

以上均是Python内置以及第三方模块提供异步IO请求模块，使用简便大大提高效率；

而对于异步IO请求的本质则是【非阻塞Socket】+【IO多路复用】

三、自定义异步非阻塞模块

1.简单示例

"""

异步非阻塞/异步IO

非阻塞: 不等待

异步: 回调函数

本质：一个线程完成并发操作（前提是执行过程中一定得有IO，这样才能让线程空闲出来去执行下一个任务）

IO 多路复用 + socket

- IO多路复用: select epoll 用于检测socket对象是否发生变化（是否连接成功，是否有数据到来）

- socket : socket客户端

- IO请求是不占用CPU的，计算型的才占用CPU

"""

import socket

import select

conn_list = []

input_list = []

for url in range(20):

client = socket.socket()

client.setblocking(False)

try:

client.connect(('61.135.169.121',80))

except BlockingIOError as e:

pass

conn_list.append(client)

input_list.append(client)

while True:

rlist, wlist, errlist = select.select(input_list, conn_list, [], 0.05)

for sock in wlist:

sock.sendall(b"GET / HTTP/1.0\r\nHost: www.baidu.com\r\n\r\n")

conn_list.remove(sock)

for sock in rlist:

data = sock.recv(8192)

sock.close()

input_list.remove(sock)

print(data)

if not input_list:

break

2.自定义异步非阻塞模块

#!/usr/bin/python3.5

# -*- coding:utf-8 -*-

"""

异步非阻塞/异步IO

非阻塞: 不等待

异步: 回调函数

本质：一个线程完成并发操作（前提是执行过程中一定得有IO，这样才能让线程空闲出来去执行下一个任务）

IO 多路复用 + socket

- IO多路复用: select epoll 用于检测socket对象是否发生变化（是否连接成功，是否有数据到来）

- socket : socket客户端

- IO请求是不占用CPU的，计算型的才占用CPU

"""

import socket

import select

from urllib import parse

class Request():

def __init__(self,sock,url,callback):

"""

初始化

:param sock: client's socket

:param callback: callback function

:param url: page url which wanna crawling

"""

self.sock = sock

self.url = url

self.callback = callback

def fileno(self):

return self.sock.fileno()

@property

def host(self):

domain = parse.urlparse(self.url)

return domain.netloc

@property

def pathinfo(self):

domain = parse.urlparse(self.url)

return domain.path

def async_request(url_list):

conn_list = []

input_list = []

for li in url_list:

sock = socket.socket()

sock.setblocking(False)

obj = Request(sock, li[0], li[1])

try:

sock.connect((obj.host,80))

except BlockingIOError as e:

pass

conn_list.append(obj)

input_list.append(obj)

while True:

# 监听socket是否已经发生变化 [request_obj,request_obj....request_obj]

# 如果有请求连接成功：wlist = [request_obj,request_obj]

# 如果有响应的数据： rlist = [request_obj,request_obj....client100]

rlist, wlist, errlist = select.select(input_list, conn_list, [], 0.05)

for obj in wlist:

# print("链接成功，发送请求...")

# obj.sock.sendall("GET {0} HTTP/1.0\r\nHost: {1}\r\n\r\n".format(obj.pathinfo,obj.host).encode('utf-8'))

obj.sock.sendall(bytes("GET {0} HTTP/1.0\r\nHost: {1}\r\n\r\n".format(obj.pathinfo,obj.host),encoding='utf-8'))

conn_list.remove(obj)

for obj in rlist:

# print("获取响应...")

data = obj.sock.recv(8192)

obj.callback(data)

obj.sock.close()

input_list.remove(obj)

if not input_list:

break

if __name__ == '__main__':

def callback1(data):

print("cnblogs...", data)

def callback2(data):

print("csdn...", data)

def callback3(data):

print("tornadoweb...", data)

url_list = [

['http://www.cnblogs.com/standby/p/7589055.html', callback1],

['http://www.cnblogs.com/wupeiqi/articles/6229292.html', callback1],

['http://blog.csdn.net/vip_wangsai/article/details/51997882', callback2],

['http://blog.csdn.net/hjhmpl123/article/details/53378068', callback2],

['http://blog.csdn.net/zcc_0015/article/details/50688145', callback2],

['http://www.tornadoweb.org/en/stable/guide.html', callback3],

['http://www.tornadoweb.org/en/stable/guide/async.html', callback3],

['http://www.tornadoweb.org/en/stable/guide/coroutines.html#python-3-5-async-and-await', callback3]

]

async_request(url_list)

3.牛逼的异步IO模块

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import select

import socket

import time

class AsyncTimeoutException(TimeoutError):

"""

请求超时异常类

"""

def __init__(self, msg):

self.msg = msg

super(AsyncTimeoutException, self).__init__(msg)

class HttpContext(object):

"""封装请求和相应的基本数据"""

def __init__(self, sock, host, port, method, url, data, callback, timeout=5):

"""

sock: 请求的客户端socket对象

host: 请求的主机名

port: 请求的端口

method: 请求方式

url: 请求的URL

data: 请求时请求体中的数据

callback: 请求完成后的回调函数

timeout: 请求的超时时间

"""

self.sock = sock

self.callback = callback

self.host = host

self.port = port

self.method = method

self.url = url

self.data = data

self.timeout = timeout

self.__start_time = time.time()

self.__buffer = []

def is_timeout(self):

"""当前请求是否已经超时"""

current_time = time.time()

if (self.__start_time + self.timeout) < current_time:

return True

def fileno(self):

"""请求sockect对象的文件描述符，用于select监听"""

return self.sock.fileno()

def write(self, data):

"""在buffer中写入响应内容"""

self.__buffer.append(data)

def finish(self, exc=None):

"""在buffer中写入响应内容完成，执行请求的回调函数"""

if not exc:

response = b''.join(self.__buffer)

self.callback(self, response, exc)

else:

self.callback(self, None, exc)

def send_request_data(self):

content = """%s %s HTTP/1.0\r\nHost: %s\r\n\r\n%s""" % (

self.method.upper(), self.url, self.host, self.data,)

return content.encode(encoding='utf8')

class AsyncRequest(object):

def __init__(self):

self.fds = []

self.connections = []

def add_request(self, host, port, method, url, data, callback, timeout):

"""创建一个要请求"""

client = socket.socket()

client.setblocking(False)

try:

client.connect((host, port))

except BlockingIOError as e:

pass

# print('已经向远程发送连接的请求')

req = HttpContext(client, host, port, method, url, data, callback, timeout)

self.connections.append(req)

self.fds.append(req)

def check_conn_timeout(self):

"""检查所有的请求，是否有已经连接超时，如果有则终止"""

timeout_list = []

for context in self.connections:

if context.is_timeout():

timeout_list.append(context)

for context in timeout_list:

context.finish(AsyncTimeoutException('请求超时'))

self.fds.remove(context)

self.connections.remove(context)

def running(self):

"""事件循环，用于检测请求的socket是否已经就绪，从而执行相关操作"""

while True:

r, w, e = select.select(self.fds, self.connections, self.fds, 0.05)

if not self.fds:

return

for context in r:

sock = context.sock

while True:

try:

data = sock.recv(8096)

if not data:

self.fds.remove(context)

context.finish()

break

else:

context.write(data)

except BlockingIOError as e:

break

except TimeoutError as e:

self.fds.remove(context)

self.connections.remove(context)

context.finish(e)

break

for context in w:

# 已经连接成功远程服务器，开始向远程发送请求数据

if context in self.fds:

data = context.send_request_data()

context.sock.sendall(data)

self.connections.remove(context)

self.check_conn_timeout()

if __name__ == '__main__':

def callback_func(context, response, ex):

"""

:param context: HttpContext对象，内部封装了请求相关信息

:param response: 请求响应内容

:param ex: 是否出现异常（如果有异常则值为异常对象；否则值为None）

:return:

"""

print(context, response, ex)

obj = AsyncRequest()

url_list = [

{'host': 'www.google.com', 'port': 80, 'method': 'GET', 'url': '/', 'data': '', 'timeout': 5,

'callback': callback_func},

{'host': 'www.baidu.com', 'port': 80, 'method': 'GET', 'url': '/', 'data': '', 'timeout': 5,

'callback': callback_func},

{'host': 'www.bing.com', 'port': 80, 'method': 'GET', 'url': '/', 'data': '', 'timeout': 5,

'callback': callback_func},

]

for item in url_list:

print(item)

obj.add_request(**item)

obj.running()

一、进程池和线程池

1.串行

2.多进程

3.进程池（1）

3.进程池（2）

4.多线程

5.线程池

二、异步非阻塞

1.asyncio示例1

2.asyncio示例2

3.asyncio示例3

4.asyncio+aiohttp示例1

或者

5.asyncio+requests示例

6.gevent+requests示例

7.Twisted示例

8.Tornado示例

三、自定义异步非阻塞模块

1.简单示例

2.自定义异步非阻塞模块

3.牛逼的异步IO模块

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