python项目练习七：自定义公告板

来源：互联网发布：叶罗丽娃娃淘宝编辑：程序博客网时间：2024/06/03 19:15

这依然是一个cgi的项目，有了前面的一个项目作为基础，这个里面没有什么难点。不过，和书上不同的是，我这里使用的数据库是mysql，所以有兴趣的童鞋，可以参考一下。

首先建立一张mysql的数据表：

CREATE TABLE messages(    id INT NOT NULL AUTO_INCREMENT,    subject VARCHAR(100) NOT NULL,    reply_to INT,    text MEDIUMTEXT NOT NULL,    PRIMARY KEY(id))

然后你要确定你的系统中已经安装了连接mysql的python模块，怎么确定呢。命令行下，进入python，然后输入import MySQLdb,注意大小写，如果没有报错，说明安装了，如果报错，从网上找python连mysql的方法，很多。

准备就绪，开始分析整个程序吧。

一个很简单的电子公告版，主要功能有，展示所有公告，查看单个公告，编辑公告，保存公告。所以根据功能建立四个文件：main.py,view.py,edit.py,save.py，每个文件，负责一个模块。

下面就上代码吧，太简单了。 main.py:

#!/usr/bin/pythonprint 'Content-type:text/html\n'print#import cgitb:cgitb.enable()import MySQLdbconn = MySQLdb.connect(db='usernet',host='127.0.0.1',user='root',passwd='root')curs = conn.cursor()print '''<html>  <head>    <title>The UserNet</title>  </head>  <body>    <h1>The UserNet</h1>'''sql = 'SELECT * FROM message'curs.execute(sql)rows = curs.fetchall()toplevel = []children = {}for row in rows:        parent_id = row[3]        if parent_id is None:                toplevel.append(row)        else:                children.setdefault(parent_id,[]).append(row)        def format(row):                print '<p><a href="view.cgi?id=%i">%s<a>' % (row[0],row[1])                try:                        kids = children[row[0]]                except KeyError:                        pass                else:                        print '<blockquote>'                        for kid in kids:                                format(kid)                        print '</blockquote>'        print '<p>'        for row in toplevel:                format(row)print '''</p><hr/><p><a href="edit.cgi">Post Message</a></p></body></html>'''

view.py

#!/usr/bin/pythonprint 'Content-type:text/html\n'import cgitb;cgitb.enable()import MySQLdbconn = MySQLdb.connect(db='usernet',host='127.0.0.1',user='root',passwd='root')curs = conn.cursor()import cgi, sysform = cgi.FieldStorage()id = form.getvalue('id')print '''<html>  <head>    <title>View Message</title>  </head>  <body>    <h1>View Message</h1>    '''try: id = int(id)except:        print 'Invalid message ID'        sys.exit()curs.execute('SELECT * FROM message WHERE id = %i' % id)rows = curs.fetchall()if not rows:        print 'Unknown message ID'        sys.exit()row = rows[0]print '''<p><b>Subject:</b> %s<br/><b>Sender:</b>%s<br/><pre>%s</pre></p><hr/><a href='main.cgi'>Back to the main page</a>|<a href="edit.cgi?reply_to=%s">Reply</a></body></html>''' % (row[1],row[2],row[4],row[0])

edit.py

#!/usr/bin/pythonprint 'Content-type:text/html\n'import cgitb;cgitb.enable()import MySQLdbconn = MySQLdb.connect(db='usernet',host='127.0.0.1',user='root',passwd='root')curs = conn.cursor()import cgi,sysform = cgi.FieldStorage()reply_to = form.getvalue('reply_to')print '''<html>  <head>    <title>Compose Message</title>  </head>  <body>    <h1>Compose Message</h1>    <form action='save.cgi' method='POST'>    '''subject = ''if reply_to is not None:        print '<input type="hidden" name="reply_to" value="%s"/>' % reply_to        curs.execute('SELECT subject FROM message WHERE id = %s' % reply_to)        subject = curs.fetchone()[0]        if not subject.startswith('Re: '):                subject = 'Re:  ' + subjectprint '''    <b>Subject:</b><br/>    <input type='text' size='40' name='subject' value='%s' /><br/>    <b>Sender:</b><br/>    <input type='text' size='40' name='sender' /><br/>    <b>Message:</b><br/>    <textarea name='text' cols='40' rows='20'></textarea><br/>    <input type='submit' value='Save'/>    </form>    <hr/>    <a href='main.cgi'>back to the main page</a>    </body>    </html>    ''' % subject

save.py

#!/usr/bin/pythonprint 'Content-type:text/html\n'import cgitb;cgitb.enable()def quote(string):        if string:                return string.replace("'","\\'")        else:                return stringimport MySQLdbconn = MySQLdb.connect(db='usernet',host='127.0.0.1',user='root',passwd='root')curs = conn.cursor()import cgi, sysform = cgi.FieldStorage()sender = quote(form.getvalue('sender'))subject = quote(form.getvalue('subject'))text = quote(form.getvalue('text'))reply_to = form.getvalue('reply_to')if not (sender and subject and text):        print 'Please supply sender,subject,text'        sys.exit()if reply_to is not None:        query = """        INSERT INTO message(reply_to,sender,subject,text)        VALUES(%d,'%s','%s','%s')""" % (int(reply_to),sender,subject,text)else:        query = """        INSERT INTO message(sender,subject,text)        VALUES('%s','%s','%s')""" % (sender,subject,text)curs.execute(query)conn.commit()print '''<html>  <head>    <title>Message Save</title>  </head>  <body>    <h1>Message Saved</h1>    <hr/>    <a href='main.cgi'>Back to the main page</a>  </body></html>s'''

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