Python程序练习(1)

2024-05-06 15:32
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from asyncio.constants import ACCEPT_RETRY_DELAY
from urllib.request import urlopen
webpage = urlopen('http://www.python.org')

#假设要提取刚才所打开网页中链接About的相对URL，可使用正则表达式
import re
text = webpage.read()
m = re.search(b'<a href="([^"]+)" .*?>about</a>',text,re.IGNORECASE)
m.group(1)
'/about/'
#如果要给下载的副本指定文件名，可通过第二个参数来提供。
urlretrieve('http://www.python.org','C:\\python_webpage.html')
#代码清单14-3 基于SocketServer的极简服务器
from socketserver import TCPServer, StreamRequestHandler
class Handler(StreamRequestHandler):
    def handle(self):
        addr = self.request.getpeername()
        print('Got connection from',addr)
        self.wfile.write('Thank you for connecting')
server = TCPServer(('',1234),Handler)
server.serve_forever()
#代码清单14-4 分叉服务器
from socketserver import TCPServer,ForkingMixIN,StreamRequestHandler
class Server(ForkingMixIN,TCPServer):pass
class Handler(StreamRequestHandler):
    def handle(self):
        addr = self.request.getpeername()
        print('Got connection from',addr)
        self wfile.write('Thank you for connecting')
server = Server(('',1234),Handler)
server.serve_forever()
#代码清单14-5 线程化服务器
from socketserver import TCPServer,ThreadingMixIN,StreamRequestHandler
class Server(ThreadingMixIN,TCPServer):pass
class Handler(StreamRequestHandler):
    def handle(self):
        addr = self.request.getpeername()
        print('Got connection from',addr)
        self.wfile.write('Thank you for connecting')
server = Server(('',1234),Handler)
server.serve_forever()
#代码清单14-6 使用select的简单服务器
import socket,select
s = socket.socket()
host = socket.gethostname()
port = 1234
s.bind((host,port))
s.listen(5)
inputs = [s]
while True:
    rs, ws, es = select.select(inputs,[],[])
    for r in rs:
        if r is s:
            c,addr = s.accept()
            print('Got connection from',addr)
            inputs.append(c)
    else:
        try:
            data = r.recv(1024)
            disconnected = not data
        except socket.error:
            disconnected = True
        if disconnected:
            print(r.getpeername(),'disconnected')
            inputs.remove(r)
        else:
            print(data)
#代码清单14-7 使用poll的简单服务器
import socket,select
s = socket.socket()
host = socket.gethostname()
port = 1234
s.bind((host,port))
fdmap = {s.fileno():s}
s.listen(5)
p = select.poll()
p.register(s)
while True:
    events = p.poll()
    for fd,event in events:
        if fd in fdmap:
            c, addr = s.accept()
            print('Got connection from',addr)
            p.register(c)
            fdmap[c.fileno()] = c
        elif event & select.POLLIN:
            data = fdmap[fd].recv(1024)
            if not data:# 没有数据 --连接已关闭
                print(fdmap[fd].getpeername(),'disconnected')
                p.unregister(fd)
                del fadmap[fd]
            else:
                print(data)
#代码清单14-8 使用Twisted创建的简单服务器
from twisted.internet import reactor
from twisted.internet.protocol import Protocol,Factory

class SimpleLogger(Protocol):
    def connectionMade(self):
        print('Got connection from',self.transport.client)
    def connectionLost(self,reason):
        print(self.transport.client,'disconnected')
    def dataReceived(self,data):
        print(data)
factory = Factory()
factory.protocol = SimpleLogger
reactor.listenTCP(1234,factory)
reactor.run()
#代码清单14-9 使用协议LineReceiver改进后的日志服务器
from twisted.internet import reactor
from twisted.internet.protocol import Factory
from twisted.protocols.basic import LineReceiver

class SimpleLogger(LineReceiver):
    def connectionMade(self):
        print('Got connection from',self.transport.client)
    def connectionLost(self,reason):
        print(self.transport.client,'disconnected')
    def lineReceived(self,line):
        print(line)
factory = Factory()
factory.protocol = SimpleLogger
reactor.listenTCP(1234,factory)
reactor.run()

#代码清单15-1 简单的屏幕抓取程序
from urllib.request import urlopen
import re
p = re.compile('<a href ="(/jobs/\\d+)/">(.*?)</a>')
text = urlopen('http://python.org/jobs').read().decode()
for url,name in p.findall(text):
    print('{} ({})'.format(name,url))
'''
<h1>Pet Shop
<h2>Complaints</h3>
<p>There is <b>no <i>way</b> at all</i> we can accept returned parrots.

<h1><i>Dead Pets</h1>
<p>Our pets may tend to rest at times,but rarely die within the warrantly period.

<i><h2>News</h2></i>

<p>We have just received <b>a really nice parrot.

<p>It's really nice.</b>

<h3><hr>The Norwegian Blue</h3>

<h4>Plumage and <hr>pining behavior</h4>
<a href="#norwegain-blue">More information<a>

<p>Features:
<body>
<li>Beautiful plumage


'''
#下面是Tidy修复后的版本：
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<h1>Pet Shop</h1>
<h2>Complaints</h2>
<p>There is <b>no <i>way</i></b> <i>at all</i> we can accept returned parrots.</p>
<h1><i>Dead Pets</i></h1>
<p><i>Our pets may tend to rest at times,but rarely die within the warrantly period.</i></p>
<h2><i>News</i></h2>
<p>We have just received <b>a really nice parrot.</b></p>
<p><b>It's really nice.</b></p>
<hr>
<h3>The Norwegain Blue</h3>
<h4>Plumage and</h4>
<hr>
<h4>pining behavior</h4>
<a href="#norwegain-blue">More information</a>
<p>Features:</p>
<ul>
<li>Beautiful plumage</li>
</ul>
</body>
</html>
#例如，假设你有一个混乱的HTML文件（messy.html），且在执行路径中包含命令行版Tidy，下面的程序将对这个文件运行Tidy并将结果打印出来：
from subprocess import Popen,PIPE

text = open('messy.html').read()
tidy = Popen('tidy',stdin=PIPE,stdout=PIPE,stderr=PIPE)

tidy.stdin.write(text.encode())
tidy.stdin.close()

print(tidy.stdout.read().decode())
#代码清单15-2 使用模块HTMLParser的屏幕抓取程序
from urllib.request import urlopen
from html.parser import HTMLParser

def isjob(url):
    try:
        a,b,c,d=url.split('/')
    except ValueError:
        return False
    return a==d==''and b=='jobs' and c.isdigit()
class Scraper(HTMLParser):
    in_link = False
    def handle_starttag(self,tag,attrs):
        attrs = dict(attrs)
        url = attrs.get('href','')
        if tag == 'a' and isjob(url):
            self.url=url
            self.in_link=True
            self.chunks=[]
    def handle_data(self,data):
        if self.in_link:
            self.chunks.append(data)
    def handle_endtag(self,tag):
        if tag == 'a' and self.in_link:
            print('{} ({})'.format(''.join(self.chunks),self.url)) 
            self.in_link=False

text = urlopen('http://python.org/jobs').read().decode()
parser = Scraper()
parser.feed(text)
parser.close()

#代码清单15-3 使用Beautiful Soup的屏幕抓取程序
from urllib.request import urlopen
from bs4 import BeautifulSoup

text = urlopen('http://python.org/jobs').read()
soup = BeautifulSoup(text,'html.parser')

jobs = set()
for job in soup.body.section('h2'):
    jobs.add('{} ({})'.format(job.a.string,job.a['href']))

print('\n'.join(sorted(jobs,key=str.lower)))

#代码清单15-4 简单的CGI脚本
#!/usr/bin/env python

print('Content-type:text/plain')
print()## 打印一个空行，以结束首部
print('Hello,world!')

#代码清单15-5 显示栈跟踪的CGI脚本（faulty.cgi）
#!/usr/bin/env python
import cgitb;cgitb.enable()

print('Content-type:text/html\n')

print(1/0)

print('Hello,world!')

#代码清单15-6 从FieldStorage中获取单个值的CGI脚本（simple2.cgi）
#!/usr/bin/env python
import cgi
from = cgi.FieldStorage()
name = form.getvalue('name','world')
print('Content-type:text/plain\n')
print('Hello,{}!'.format(name))
#代码清单15-7 包含HTML表单的问候脚本（simple3.cgi）
#!/usr/bin/env python
import cgi
form = cgi.FieldStorage()
name = form.getvalue('name','world')
print("""Content-type:text/html
<html>
    <head>
        <title>Greeting Page</title>
    </head>
    <body>
        <h1>Hello,{}!</h1>

        <form action = 'simple3.cgi'>
        Change name <input type = 'text' name='name' />
        <input type = 'submit' />
        </form>
    </body>
</html>
""".format(name))
'''
在这个脚本开头，与以前一样获取CGI参数name，并将默认值设置为'world'。如果在浏览器
中打开这个脚本时没有提交任何值，将使用默认值。
接下来，打印了一个简单的HTML页面，其中的标题包含参数name的值。另外，这个页面还
包含一个HTML表单，该表单的属性action被设置为脚本的名称（simple3.cgi）。这意味着提交表
单后，将再次运行这个脚本。这个表单只包含一个输入元素——名为name的文本框。因此，如果
你在文本框中输入新名字并提交表单，标题将发生变化，因为现在参数name包含值。
'''

#https://wiki.python.org/moin/WebFrameworks
#JSON，http://www.json.org

#代码清单16-1 简单的测试程序
from area import rect_area

height = 3
width = 4
correct_answer = 12
answer = rect_area(height,width)
if answer == correct_answer:
    print('Test passed')
else:
    print('Test failed')

#代码清单16-3 使用模块subprocess调用外部检查器
import unittest,my_math
from subprocess import Popen,PIPE
class ProductTestCase(unittest.TestCase):
    #在这里插入以前的测试
    def test_with_PyChecker(self):
        cmd = 'pychecker','-Q',my_math.__file__.rstrip('c')
        pychecker = Popen(cmd,stdout=PIPE,stderr=PIPE)
        self.assertEqual(pychecker.stdout.read(),'')

    def test_with_PyLint(self):
        cmd = 'pylint','-rn','my_math'
        pylint = Popen(cmd,stdout=PIPE,stderr=PIPE)
        self.assertEqual(pylint.stdout.read(),'')

if __name__ =='__main__':unittest.main()

#代码清单17-1 一个简单的Java类（JythonTest.java）

public class JythonTest {
    public void greeting(){
        System.out.println("Hello,world!");
    }

}

#$ javac JythonTest.java

#代码清单17-2 一个简单的C#类（IronPythonTest.cs）
using System;
namespace FePyTest{
    public class IronPythonTest{
        public void greeting(){
            Console.WriteLine("Hello,world");
        }
    }
}

#对于Microsoft .NET，命令如下：
#csc.exe /t:library IronPythonTest.cs

#《C语言入门经典（第5版）》 《C程序设计语言（第2版）》

#NumPy（http://numpy.org）


#一个简单的检测回文的C语言函数（palindrome.c）
#include <string.h>

int is_palindrome(char *text){
    int i, n=strlen(text);
    for(i=0;I<=n/2;++i){
        if(text[i] != text[n-i-1]) return 0;
    }
    return 1;
}

#代码清单17-4 检测回文的Python函数
def is_palindrome(text):
    n = len(text)
    for i in range(len(text) // 2):
        if text[i] != text[n-i-1]:
            return False
    return True

#代码清单17-5 回文检测库的接口（palindrome.i）
%module palindrome

%{
    #include <string.h>
%}

extern int is_palindrome(char *text);

#下面是一个在Solaris系统中使用编译器cc的示例（这里假设$PYTHON_HOME指向Python安装目录）：

# cc -c palindrome.c
# cc -I$PYTHON_HOME -I$PYTHON_HOME/Include -c palindrome_wrap.c
# cc -G palidrome.o palindrome_wrap.o -o _palindrome.so