Linux下安裝Python3.9

 

centos安裝python3.9.0
 
1.先決條件：
sudo yum install gcc openssl-devel bzip2-devel libffi-devel zlib-devel
 
2.下載：
各版本地址：https://www.python.org/ftp/python
wget https://www.python.org/ftp/python/3.9.0/Python-3.9.0.tgz 
 
3.解壓：
tar xzf Python-3.9.0.tgz 
 
4.安裝：
cd Python-3.9.0 
sudo ./configure --enable-optimizations 
sudo make altinstall 
 
5.創建虛擬環境（for flask project，僅安裝python則忽略）
virtualenv -p /usr/local/bin/python3.9 venv
source ./venv/bin/activate
pip install -r requirements.txt
 
 
 
遇到的問題：
1.yum源問題導致gcc安裝失敗
（1）執行sudo ./configure --enable-optimizations報缺少C編譯器
configure: error: in `/opt/python39/Python-3.9.0':
configure: error: no acceptable C compiler found in $PATH
See `config.log' for more details
 
嘗試執行：yum install gcc 時報yum庫libgomp版本沖突
Error:  Multilib version problems found. This often means that the root
       cause is something else and multilib version checking is just
       pointing out that there is a problem. Eg.:
    ... ...
       Protected multilib versions: libgomp-4.8.5-4.el7.i686 != libgomp-4.8.5-36.el7_6.2.x86_64
rpm -qa|grep libgomp: libgomp-4.8.5-36.el7_6.2.x86_64
 
嘗試執行yum install gcc --setopt=protected_multilib=false忽略protected multilib，依然報錯
Transaction check error:
  package libgomp-4.8.5-36.el7_6.2.x86_64 (which is newer than libgomp-4.8.5-4.el7.i686) is already installed
 
目測是該yum源中libgomp版本還是不符合gcc依賴，只好嘗試升級yum源到國內阿里源
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
yum makecache
vi /etc/yum.repos.d/CentOS-Base.repo  #將所有http改為https，注意備份該文件(vi替換命令 :1,$s/http/https/g)
yum update
yum install gcc
 
 
2.升級gcc版本
centos7使用yum install gcc后默認安裝版本是gcc 4.8.5，版本比較低，升級gcc版本：
sudo yum install centos-release-scl
sudo yum install devtoolset-7
scl enable devtoolset-7 bash
gcc --version  # 升級后為7.3.1
 
 
3.pip install -r requirements.txt報錯，降低setuptools版本，新版本setuptools移除了Feature
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/tmp/pip-install-wduw3u48/markupsafe/setup.py", line 6, in <module>
     from setuptools import setup, Extension, Feature
ImportError: cannot import name 'Feature' from 'setuptools'
這個通常會在安裝 Flask 項目的依賴時發生，因為 MarkupSafe 是 Flask 的依賴之一
原因是因為 Python 打包工具 setuptools 在 46.0.0 版本刪掉了棄用的 Feature，
更新 MarkupSafe 到最新版本
pip install --upgrade pip setuptools==45.2.0
 
 
4.啟動項目報警告
UserWarning: Could not import the lzma module. Your installed Python is incomplete. 
Attempting to use lzma compression will result in a RuntimeError
重新編譯python：
sudo yum install -y xz-devel
sudo ./configure --enable-optimizations
sudo make altinstall
 
 
5.啟動項目報警告
RuntimeWarning: line buffering (buffering=1) isn't supported in binary mode, 
the default buffer size will be used
remember ... it is not a bug, it's a feature
這個是gunicorn 19.x有可能報的問題，可以選擇升級gunicorn解決：
pip install gunicorn==20.0.4
 
 
 
參考：
https://tecadmin.net/install-python-3-9-on-centos/  （安裝python39）
https://developer.aliyun.com/article/704987  （配置阿里鏡像）
https://www.itcoder.tech/posts/how-to-install-gcc-compiler-on-centos-7/ （升級gcc）
https://zhuanlan.zhihu.com/p/127820010  （MarkupSafe報錯）
https://stackoverflow.com/questions/57743230/userwarning-could-not-import-the-lzma-module-your-installed-python-is-incomple（lzma問題）
https://askubuntu.com/questions/1216292/python3-runtimewarning-line-buffering-buffering-1-isnt-supported-in-binary-m （gunicorn line buffer問題）