Linux之python版本升级

一、前言
  升级glibc的时候根据INSTALL升级说明，要求python版本3.4以上。所以需要对python版本进行升级。centos7默认安装的python版本为2.7.5，python通过yum安装也只能安装2.7.5版本，python3可以通过yum安装3.6.8版本。如果需要更高的版本，只能通过源码编译安装。此博文介绍源码安装方式升级python和python3版本，源码编译安装要求操作系统已经安装了gcc。环境说明如下：

操作系统：centos7.6
python版本：升级前版本2.7.5，升级后2.7.18
python3版本：升级前3.6.8，升级后版本3.8.8
二、python安装步骤
1、查看当前python版本
[root@s143 ~]# python -V
Python 2.7.5

2、yum安装python
[root@s143 ~]# yum install -y python2
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Package python-2.7.5-90.el7.x86_64 already installed and latest version
Nothing to do

3、yum安装python3
[root@s143 ~]# yum install -y python3
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Installed:
python3.x86_64 0:3.6.8-18.el7

Dependency Installed:
libtirpc.x86_64 0:0.2.4-0.16.el7 python3-libs.x86_64 0:3.6.8-18.el7 python3-pip.noarch 0:9.0.3-8.el7 python3-setuptools.noarch 0:39.2.0-10.el7

Complete!
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1、下载python新版本
[root@s143 opt]# wget https://www.python.org/ftp/python/2.7.18/Python-2.7.18.tgz

2、解压软件包
[root@s143 opt]# tar -zxvf Python-2.7.18.tgz

3、预编译软件包
[root@s143 opt]# cd Python-2.7.18
[root@s143 Python-2.7.18]# ./configure --prefix=/usr

4、编译软件包
[root@s143 Python-2.7.18]# make
…
running build_scripts
creating build/scripts-2.7
copying and adjusting /opt/Python-2.7.18/Tools/scripts/pydoc -> build/scripts-2.7
copying and adjusting /opt/Python-2.7.18/Tools/scripts/idle -> build/scripts-2.7
copying and adjusting /opt/Python-2.7.18/Tools/scripts/2to3 -> build/scripts-2.7
copying and adjusting /opt/Python-2.7.18/Lib/smtpd.py -> build/scripts-2.7
changing mode of build/scripts-2.7/pydoc from 644 to 755
changing mode of build/scripts-2.7/idle from 644 to 755
changing mode of build/scripts-2.7/2to3 from 644 to 755
changing mode of build/scripts-2.7/smtpd.py from 644 to 755
/usr/bin/install -c -m 644 ./Tools/gdb/libpython.py python-gdb.py

5、安装软件包
[root@s143 Python-2.7.18]# make install

6、检查升级后的版本
[root@s143 Python-2.7.18]# python -V
Python 2.7.18

四、python3升级步骤
1、下载安装包
[root@s143 opt]# wget https://www.python.org/ftp/python/3.8.8/Python-3.8.8.tgz

2、解压软件包
[root@s143 opt]# tar -zxvf Python-3.8.8.tgz

3、预编译
注意在编译结束后会有提示"If you want a release build with all stable optimizations active (PGO, etc),please run ./configure --enable-optimizations"，加上–enable-optimizations预编译的话后续编译会报错“Could not import runpy module ”，原因是gcc版本太低，enable-optimizations参数要求gcc版本8.1.0以上。

[root@s143 opt]# cd Python-3.8.8
[root@s143 Python-3.8.8]# ./configure

4、编译
[root@s143 Python-3.8.8]# make
…
if test `uname -s` = Darwin; then
cp python-config.py python-config;
fi

5、编译安装
[root@s143 Python-3.8.8]# make install
…
Collecting setuptools
Collecting pip
Installing collected packages: setuptools, pip
Successfully installed pip-18.1 setuptools-40.6.2

6、升级后版本检查
[root@s143 Python-3.6.10]# python3 -V
Python 3.8.8

五、QA
1、安装python3.8.8的时候报错zlib not available
报错信息：zipimport.ZipImportError: can’t decompress data; zlib not available
报错原因：没有安装zlib模块
解决方案：安装zlib模块
[root@s143 bin]# yum install -y zlib*
2、安装完python之后yum报错File “/usr/bin/yum”, line 30
报错信息：File “/usr/bin/yum”, line 30
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