当前位置：首页 > news >正文

Python高性能编程

news 2026/3/31 15:34:28

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

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

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

相关文章：