liunx上升级python2至python3

一.背景介绍

虚拟机的liunx系统CentOS7自带了python2.7.5，为使用方便需要换成最新的版本3.10.4

二.安装方法

1.安装升级GCC

yum install -y gcc* openssl openssl-devel ncurses-devel.x86_64  bzip2-devel sqlite-devel  zlib python-devel mysql-devel openldap-devel

2.下载python安装包

wget https://www.python.org/ftp/python/3.10.4/Python-3.10.4.tar.xz

3.解压

tar xvf Python-3.10.4.tar.xz

4.编译安装

cd Python-3.10.4
mkdir -p /usr/local/python3
./configure --prefix=/usr/local/python3
make && make install

5.将老版本python更换

mv /usr/bin/python /usr/bin/python2.7.5

6.更换默认python

ln -s /usr/local/python3/bin/python3 /usr/bin/python
ln -s /usr/local/python3/bin/pip3.10 /usr/bin/pip

7.修改 yum以及urlgrabber-ext-down中的python

将#!/usr/bin/python改为 #!/usr/bin/python2.7.5

vim /usr/bin/yum
vim /usr/libexec/urlgrabber-ext-down

PS:python3.10.4是默认安装pip的,所以不需要另行安装setuptools和pip.

 再次查看python版本已经升级：

 8.发现pip下载时候报错

解决方案1：pip设置后重装python（并未解决）

cd Python-3.10.4
进入目录下，依次执行以下3条命令
./configure –with-ssl
make
sudo make install

解决方案2：升级openssl版本并编译安装（解决）

#1.下载openssl

wget https://www.openssl.org/source/openssl-1.1.1o.tar.gz --no-check-certificate
tar zxvf openssl-1.1.1o.tar.gz
cd openssl-1.1.1o.tar.gz

# 2.编译安装

./config --prefix=/usr/local/openssl no-zlib #不需要zlib

make

make install

# 3.备份原配置

mv /usr/bin/openssl /usr/bin/openssl.bak

mv /usr/include/openssl/ /usr/include/openssl.bak

# 4.新版配置
ln -s /usr/local/openssl/include/openssl /usr/include/openssl
ln -s /usr/local/openssl/lib/libssl.so.1.1 /usr/local/lib64/libssl.so
ln -s /usr/local/openssl/bin/openssl /usr/bin/openssl

# 5.修改系统配置
## 写入openssl库文件的搜索路径
echo "/usr/local/openssl/lib" >> /etc/ld.so.conf
## 使修改后的/etc/ld.so.conf生效
ldconfig -v
# 6.查看openssl版本
openssl version
#7 此时重新安装python

cd Python-3.10.4

./configure --prefix=/usr/local/python3 --with-openssl=/usr/local/openssl

make

make install

#8.此时pip命令安装时报需要升级，升级

/usr/local/python3/bin/python3.10 -m pip install --upgrade pip

#9.升级pip完成后下载成功