升级python，安装pip，Django

rtwer

centos6.6 系统默认python版本是python2.6.6.目前这个版本算很低了，主流是使用python2.7或者python3.0了；python2.6.6仅可以支持到Django1.3.7，这个Django版本也太低了，很多特性不可使用，现在就升级到python2.6.6到python2.7.9，然后安装pip，通过pip安装Django的高版本！

1. 下载python2.7.9
http://www.python.org/ftp/python/

2. 解压文件
tarxvf Python-2.7.9.tar.bz2

3. 创建安装目录
mkdir/usr/local/python27

4. 安装python
./configure--prefix=/usr/local/python27
make
make install

5. 修改老版本的ln指向（注意：这里修改后，可能会影响yum的使用）
[root@centospip-1.5.6]# mv /usr/bin/python /usr/bin/python2.6.6

[iyunv@centos pip-1.5.6]# ln -s /usr/local/python27/bin/python/usr/bin/python

报错：

[iyunv@centos pip-1.5.6]# yum clean all

There was a problem importing one of the Python modules

required to run yum. The error leading to this problem was:

  No module named yum

Please install a package which provides this module, or

verify that the module is installed correctly.

It's possible that the above module doesn't match the

current version of Python, which is:

2.7.9 (default, Dec 17 2014, 16:50:28)

[GCC 4.4.7 20120313 (Red Hat 4.4.7-11)]

If you cannot solve this problem yourself, please go to

the yum faq at:

http://yum.baseurl.org/wiki/Faq

错误原因：错误信息描述为yum 所依赖的python不相符，请安装相对应的python即可

[iyunv@centos pip-1.5.6]# rpm -qa | grep yum

yum-metadata-parser-1.1.2-16.el6.x86_64

yum-plugin-fastestmirror-1.1.30-30.el6.noarch

PackageKit-yum-0.5.8-23.el6.x86_64

yum-3.2.29-60.el6.centos.noarch

yum-plugin-security-1.1.30-30.el6.noarch

PackageKit-yum-plugin-0.5.8-23.el6.x86_64

yum-utils-1.1.30-30.el6.noarch

You have new mail in /var/spool/mail/root

[iyunv@centos pip-1.5.6]# whereis python

python: /usr/bin/python2.6 /usr/bin/python /usr/lib/python2.6/usr/lib64/python2.6 /usr/include/python2.6/usr/share/man/man1/python.1.gz

[iyunv@centos pip-1.5.6]# python -V

Python 2.7.9

现在系统上有两个版本的python！！！yum是由python写的！

一个是我刚安装的2.7.9,一个是centos默认安装的2.6.6

但是我执行了：

[iyunv@centos pip-1.5.6]# mv /usr/bin/python /usr/bin/python2.6.6

[iyunv@centos pip-1.5.6]# ln -s /usr/local/python27/bin/python/usr/bin/python

[iyunv@centos Downloads]# python -V

Python 2.7.9

[iyunv@centos pip-1.5.6]# which yum

/usr/bin/yum     这个文件使用了python，看来这个yum不支持，2.7.9高版本的python

解决：

[iyunv@centos pip-1.5.6]# vim /usr/bin/yum

把python环境改成python2.6.6

pip：python软件包管理工具

下面安装pip：

安装之前：先安装opensslopenssl-devel,后面你就会知道

https://pip.pypa.io/en/latest/installing.html

pip使用文档：

https://pypi.python.org/pypi/pip#downloads

我安装和下载：

[iyunv@centos pip-1.5.6]# pwd

/tmp/pip-1.5.6

[iyunv@centos pip-1.5.6]# ls

AUTHORS.txt  docs         pip.egg-info  setup.cfg

build        LICENSE.txt  PKG-INFO      setup.py

CHANGES.txt  MANIFEST.in  PROJECT.txt   setuptools-8.0.4

dist         pip          README.rst    setuptools-8.0.4.zip

报错：ImportError:cannot import name HTTPSHandler

[iyunv@centos pip-1.5.6]# pip

Traceback (most recent call last):

File "/usr/bin/pip", line 9, in <module>

load_entry_point('pip==1.5.6', 'console_scripts', 'pip')()

File "build/bdist.linux-x86_64/egg/pkg_resources.py",line 458, in load_entry_point

File "build/bdist.linux-x86_64/egg/pkg_resources.py",line 2545, in load_entry_point

File "build/bdist.linux-x86_64/egg/pkg_resources.py",line 2244, in load

File"/usr/local/python27/lib/python2.7/site-packages/pip-1.5.6-py2.7.egg/pip/__init__.py",line 10, in <module>

from pip.util import get_installed_distributions, get_prog

File"/usr/local/python27/lib/python2.7/site-packages/pip-1.5.6-py2.7.egg/pip/util.py",line 18, in <module>

from pip._vendor.distlib import version

File"/usr/local/python27/lib/python2.7/site-packages/pip-1.5.6-py2.7.egg/pip/_vendor/distlib/version.py",line 14, in <module>

from .compat import string_types

File"/usr/local/python27/lib/python2.7/site-packages/pip-1.5.6-py2.7.egg/pip/_vendor/distlib/compat.py",line 31, in <module>

from urllib2 import (Request, urlopen, URLError, HTTPError,

ImportError: cannot import name HTTPSHandler

解决：

yuminstall -y openssl   openssl-devel

然后重新编译python！！

安装Django：版本：1.7.1

[iyunv@centos Downloads]# pipinstall Django

Downloading/unpacking Django

DownloadingDjango-1.7.1-py2.py3-none-any.whl (7.4MB):  20%  1.5MB

但是，悲剧的是：

python升级之后，KVM的图形管理界面就打不开了，但是KVM虚拟机都没有挂掉，只是说，图形管理界面挂了！！！

报错：
[iyunv@centos ~]#virt-manager
Traceback (most recent calllast):
File"/usr/share/virt-manager/virt-manager.py", line 400, in<module>
main()
File"/usr/share/virt-manager/virt-manager.py", line 251, inmain
from virtManager importcli
File"/usr/share/virt-manager/virtManager/cli.py", line 29, in<module>
import libvirt
ImportError:No module named libvirt
You have new mail in/var/spool/mail/root

解决:
[iyunv@centos ~]#/usr/bin/python2.6.6 -V
Python 2.6.6
[iyunv@centos ~]#/usr/bin/python2.7 -V
Python 2.7.9

使用python2.6.6启动virt-manager:
[iyunv@centos ~]#/usr/bin/python2.6.6 "/usr/share/virt-manager/virt-manager.py"