CentOS7安装Python3（保留Python2）

 

 

查看当前python版本

[root@localhost]# python -V

 

查看路径

[root@localhost]# which python

[root@localhost]# cd /usr/bin/

 

确定当前python的依赖

[root@localhost bin]# ll python*

 

安装依赖

[root@localhost bin]# yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make

 

备份python2

[root@localhost bin]# mv python python.bak

 

新建python3目录

[root@localhost bin]# mkdir /usr/local/python3

[root@localhost bin]# cd /usr/local/python3/

 

下载python3

[root@localhost python3]# wget https://www.python.org/ftp/python/3.6.3/Python-3.6.3.tgz

[root@localhost python3]# tar -xvf Python-3.6.3.tgz

 

编译安装

[root@localhost python3]# cd Python-3.6.3

[root@localhost Python-3.6.3]# ./configure --prefix=/usr/local/python3Dir

[root@localhost Python-3.6.3]# make

[root@localhost Python-3.6.3]# make install

 

创建软连接

[root@localhost Python-3.6.3]# ln -s /usr/local/python3Dir/bin/python3 /usr/bin/python

 

测试（键入python默认打开python3  ，  键入python2才是python2.7）

[root@localhost bin]# python

Python 3.6.3 (default, Apr  9 2019, 11:33:44)

[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux

Type "help", "copyright", "credits" or "license" for more information.

>>>

[root@localhost bin]# python2

Python 2.7.5 (default, Oct 30 2018, 23:45:53)

[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> 

 

 

前面将系统预安装的 Python 修改为了 python2 所以咱们要修改相应的配置文件，要不然后面的操作会报错（修改之前最好先做好备份）

修改yum文件

[root@localhost bin]# sudo vi /usr/bin/yum

#将第一行指定的python版本改为python2.7

#!/usr/bin/python 改为 #!/usr/bin/python2.7

 

urlgrabber文件修改

[root@localhost bin]# sudo vi /usr/libexec/urlgrabber-ext-down

#将第一行指定的python版本改为python2.7

 

yum-config-manager修改

[root@localhost bin]# sudo vi /usr/bin/yum-config-manager

#将第一行指定的python版本改为python2.7

 

如果已安装了pip（python2.7的），需要将/usr/bin/pip文件中的python该为2.7

#!/usr/bin/python2.7

 

 

---

 

安装pip3

 

 

[root@localhost bin]# cd /usr/local/python3/

 

下载安装setuptools

[root@localhost python3]# wget --no-check-certificate  https://pypi.python.org/packages/source/s/setuptools/setuptools-19.6.tar.gz#md5=c607dd118eae682c44ed146367a17e26

 

[root@localhost python3]# tar -zxvf setuptools-19.6.tar.gz

 

[root@localhost python3]# cd setuptools-19.6

 

[root@localhost setuptools-19.6]# python3 setup.py build

 

[root@localhost setuptools-19.6]#python3 setup.py install

 

 

 

[root@localhost bin]# cd /usr/local/python3/

 

再安装pip

[root@localhost python3]# wget --no-check-certificate  https://pypi.python.org/packages/source/p/pip/pip-8.0.2.tar.gz#md5=3a73c4188f8dbad6a1e6f6d44d117eeb

 

[root@localhost python3]# tar -zxvf pip-8.0.2.tar.gz

 

[root@localhost python3]# cd pip-8.0.2

 

[root@localhost pip-8.0.2]# python3 setup.py build

 

[root@localhost pip-8.0.2]# python3 setup.py install

 

 

安装完的pip3路径为/usr/local/python3Dir/bin/pip3

 

为pip3创建软连接

[root@localhost bin]# ln -s /usr/local/python3Dir/bin/pip3 /usr/bin/pip3

 

 

测试

[root@localhost bin]# pip -V

pip 19.0.3 from /usr/lib/python2.7/site-packages/pip-19.0.3-py2.7.egg/pip (python 2.7)

 

[root@localhost bin]# pip3 -V

pip 19.0.3 from /usr/local/python3Dir/lib/python3.6/site-packages/pip (python 3.6)