[root@VM-0-2-centos webapps]# which python3
/usr/bin/python3

https://danieleriksson.net/2017/02/08/how-to-install-latest-python-on-centos/

Use “make altinstall” to prevent problems

It is critical that you use make altinstall when you install your custom version of Python. If you use the normal make install you will end up with two different versions of Python in the filesystem both named python. This can lead to problems that are very hard to diagnose.

# Python 3.8.5:

wget http://python.org/ftp/python/3.8.5/Python-3.8.5.tar.xz

tar xf Python-3.8.5.tar.xz

cdPython-3.8.5

./configure--prefix=/usr/local--enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"

make&&makealtinstall

# pwd
/usr/local/bin
# ls py*
pydoc3  pydoc3.8  python3.8  python3.8-config
/usr/local/bin/python3.8

# /usr/local/bin/python3.8
Python 3.8.5 (default, Sep  4 2020, 19:48:39)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cytpes
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'cytpes'
>>> exit()

# python3.8
Python 3.8.5 (default, Sep  4 2020, 19:48:39)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cyptes
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'cyptes'

wget https://bootstrap.pypa.io/get-pip.py

python3.8 get-pip.py

# yum install libffi-devel
已加载插件：fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirror.lzu.edu.cn
 * elrepo: mirrors.tuna.tsinghua.edu.cn
 * epel: my.mirrors.thegigabit.com
 * extras: mirror.lzu.edu.cn
 * updates: mirror.lzu.edu.cn
软件包 libffi-devel-3.0.13-19.el7.x86_64 已安装并且是最新版本
无须任何处理