《Python核心编程 第二版》.(Wesley J. Chun ).[高清PDF中文版]
一、CentOS中安装python，yum install python，我通过这个命令安装python，默认安装的是2.6的版本，但是当我把python 2.6安装完成后，发现cobbler的WEB管理页面无法打开了，查看apahce的错误日志：
[Sun Jul 07 20:13:01 2013] [error] [client 192.168.21.94] ImportError: cannot import name urandom
[Sun Jul 07 20:13:02 2013] [error] [client 192.168.21.94] File does not exist: /var/www/html/favicon.ico
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] mod_wsgi (pid=10816): Target WSGI script '/usr/share/cobbler/web/cobbler.w
sgi' cannot be loaded as Python module.
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] mod_wsgi (pid=10816): Exception occurred processing WSGI script '/usr/shar
e/cobbler/web/cobbler.wsgi'.
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] Traceback (most recent call last):
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/share/cobbler/web/cobbler.wsgi", line 9, in <module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] import django.core.handlers.wsgi
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib/python2.6/site-packages/django/core/handlers/wsgi.py", li
ne 10, in <module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] from django import http
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib/python2.6/site-packages/django/http/__init__.py", line 12
3, in <module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] from django.utils.http import cookie_date
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib/python2.6/site-packages/django/utils/http.py", line 7, in
<module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] from email.Utils import formatdate
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib64/python2.6/email/__init__.py", line 79, in __getattr__
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] __import__(self.__name__)
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib64/python2.6/email/utils.py", line 27, in <module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] import random
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] File "/usr/lib64/python2.6/random.py", line 47, in <module>
[Sun Jul 07 20:31:09 2013] [error] [client 192.168.21.94] from os import urandom as _urandom
缺少urandom模块，python2.6版本里默认没有这个模块，随即将python升级到2.7版本。
升级过程：
1、下载Python 2.7源码：
wget
下载
2、解压源码包：
tar -zxvf Python-2.7.2.tgz
3、编译：
cd Python-2.7.2
./configure --prefix=/usr
4、make&&make install
安装完成后测试web界面可以正常打开了，但是使用yum安装软件的时候会发现不能使用，原因是yum与python有依赖关系，yum是急于python写的，运行yum命令时会调用pyton；
vi /usr/bin/yum
将#！/usr/bin/pyton 改成：#！/usr/bin/pyton2.6，改成你系统默认的版本即可，不然他会调用高版本的python软件包，但是是找不到的，需要做相关配置才行，这里为了方便就直接改了就可以使用了。