Centos7使用Python3

1.安装python3替换python2.7

[root@Python src]# wget https://www.python.org/ftp/python/3.5.4/Python-3.5.4.tar.xz
[root@Python src]# yum install zlib-devel zlib openssl
[root@Python src]# tar xf Python-3.5.4.tar.xz
#可能需要一些库文件
[root@Python src]# yum groupinstall "Development tools"
[root@Python src]# yum install readline-devel
[root@Python src]# cd Python-3.5.4/
[root@Python Python-3.5.4]# ./configure --prefix=/usr/local/python3 --with-ssl
[root@Python Python-3.5.4]# make && make install
[root@Python ~]# cp /usr/bin/python2.7 /usr/bin/python2.7.bak
[root@Python ~]# rm -f /usr/bin/python
[root@Python ~]# ln -s /usr/local/python3/bin/python3.5 /usr/bin/python
[root@Python ~]# vi /usr/bin/yum
#!/usr/bin/python2
[root@Python ~]# vi /usr/libexec/urlgrabber-ext-down
#! /usr/bin/python2.7
[root@Python ~]# python
Python 3.5.4 (default, Feb  6 2018, 02:52:38)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-4)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

2. 安装pip3

#安装setuptools
[root@Python src]# wget --no-check-certificate  https://pypi.python.org/packages/source/s/setuptools/setuptools-19.6.tar.gz#md5=c607dd118eae682c44ed146367a17e26
[root@Python src]# yum install zlib-devel zlib
[root@Python src]# tar xf setuptools-19.6.tar.gz
[root@Python src]# cd setuptools-19.6/
[root@Python setuptools-19.6]# python setup.py build
[root@Python setuptools-19.6]# cd /usr/local/src/Python-3.5.4/
[root@Python Python-3.5.4]# make && make install
#安装pip3
[root@Python src]# wget https://pypi.python.org/packages/11/b6/abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/pip-9.0.1.tar.gz
[root@Python src]#  tar xf pip-9.0.1.tar.gz
[root@Python src]#  cd pip-9.0.1
[root@Python pip-9.0.1]# python setup.py build
[root@Python pip-9.0.1]# python setup.py install
#基本安装完成
[root@Python pip-9.0.1]# python -m pip install paramiko
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting paramiko
  Could not fetch URL https://pypi.python.org/simple/paramiko/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
  Could not find a version that satisfies the requirement paramiko (from versions: )
No matching distribution found for paramiko
[root@Python pip-9.0.1]# yum install openssl-devel
[root@Python bin]# ln -s /usr/local/python3/bin/pip3 /usr/bin/pip