Python2 Upgrade to Python3

install GCC readline* and so on, or it will go wrong.

Yum install gcc readline*-y

1. From the Python website to the package that gets Python3, switch to directory/USR/LOCAL/SRC

#wget HTTPS://WWW.PYTHON.ORG/FTP/PYTHON/3.5.1/PYTHON-3.5.1.TAR.XZ

2. Extract the following command using the command:

1 xz-d python-3.5.1.tar.xz2 tar-xf Python-3.5.1.tar

3. Create directory--python3.5 under/usr/local path, install directory for 4th step

$mkdir/usr/local/python3.5

4. Compile the installation (pip-7.1.2 will be installed automatically)

$CD/usr/local/src/python-3.5.1#./configure--prefix=/usr/local/python3.5#make all#make install#make clean#make Distclean

5. Enter the absolute path of the installation to check if the installation is successful

$/usr/local/python3.5/bin/python3.5-v Python 3.5.1

6. View the environment variables, start Python by default in the order of path to find, in/usr/bin python at this time is Python2.6.

$echo $PATH/usr/lib/qt-3.3/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/gordon/bin

7. Modify soft connection, point to python3.5 when starting Python

Backup pythonmv/usr/bin/python/usr/bin/python2.6.6 sudo ln-s/usr/local/python3.5/bin/python3/usr/bin/python

8. Verify that python3.5 is started by default

$ python-v Python 3.5.1

9. After the upgrade of Python, Yum is not working, need to modify/usr/bin/yum, instead use python2.6.6

#!/usr/bin/python2.6.6

Python2 Upgrade to Python3