centos中使用python遇到的几个问题

用python搞了一个从excel中读取cobbler节点信息并加入cobbler中的脚本，运行的过程中出了不少问题，这里记录下来，方便日后查找！

一、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 http://www.python.org/ftp/python/2.7.2/Python-2.7.2.tgz

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。

二、在安装了python2.7后执行cobbler的相关命令也会有问题

[root@cobbler scripts]# ./addnode2.py cobbler.xls
add test1 aa:bb:cc:dd 19:2.:16:8.:0.:2
add test2 aa:bb:cc:dd 19:2.:16:8.:0.:3
[root@cobbler scripts]# Traceback (most recent call last):
  File "/usr/bin/cobbler", line 17, in <module>
    import cobbler.cli as app
ImportError: No module named cobbler.cli
Traceback (most recent call last):
  File "/usr/bin/cobbler", line 17, in <module>
    import cobbler.cli as app
ImportError: No module named cobbler.cli

[root@cobbler scripts]# cobbler get-loaders
Traceback (most recent call last):
  File "/usr/bin/cobbler", line 17, in <module>
    import cobbler.cli as app
ImportError: No module named cobbler.cli

这也是由于python版本导致的，同样：vi /usr/bin/cobbler

将调用的python版本修改为2.6即可。

三、补充：关于安装EasyInstall 遇到的问题：

下载：

wget http://pypi.python.org/packages/2.7/s/setuptools/setuptools-0.6c11-py2.7.egg

安装：

sh  setuptools-0.6c11-py2.7.egg

报错：

Traceback (most recent call last):
File "<string>", line 1, in <module>
zipimport.ZipImportError: can't decompress data; zlib not available

解决方法：

1、安装依赖zlib、zlib-devel

2、重新编译安装Python

./configure
编辑Modules/Setup文件
找到下面这句，去掉注释
#zlib zlibmodule.c -I$(prefix)/include -L$(exec_prefix)/lib -lz
重新编译安装：make & make install