這裡寫目錄標題

• 1. 編譯安裝 Python
• • 1.1. 專題: 同系統多版本 Python 問題
  • • 1.1.1. altinstall bininstall maninstall
    • 1.1.2. 兼容性修正
    • • 1.1.2.1. Redhat/CentOS 系
      • 1.1.2.2. Debian/Ubuntu 系
    • 1.1.3. 快速虛擬化環境工具
  • 1.2. Step 1: Install Python Dependencies
  • 1.3. Step 2: Download latest Python 3.9 Archive
  • 1.4. Step 3: Install Python 3.9 on CentOS 8 / CentOS 7

1. 編譯安裝 Python

在 CentOS 上因為自帶的 Python 版本比較舊，所以要安裝高版本的 Python 但同時要求不能影響原來的 python3 命令。

先不急著動手，可以先看看關於多版本的專題。

1.1. 專題: 同系統多版本 Python 問題

非常不建議直接覆蓋當前系統的 python 和 python3 命令，Python 每個版本之間多少有點不兼容問題，處理起來非常麻煩，萬一系統用到了，就是個大問題。

Building Python: make install can overwrite or masquerade the python3 binary. make altinstall is therefore recommended instead of make install since it only installs exec_prefix/bin/pythonversion.

If you want it to install to, for example, /usr/bin instead of the default (/usr/local/bin in ubuntu/debian), then instead of ./configure, type ./configure --prefix=/usr when told to use it in the guide.

For in your $HOME/bin directory, use --prefix=$HOME.

If it doesn’t exist, add $HOME/bin to your $PATH like this:

$ export PATH=$HOME/bin:$PATH

This may already be in your .bashrc in ubuntu, and others. If it is, when you next log in, $HOME/bin will be added to your $PATH automatically.

1.1.1. altinstall bininstall maninstall

Let’s take a look at the generated Makefile!

First, the install target:

install: altinstall bininstall maninstall

It does everything altinstall does, along with bininstall and maninstall

Here’s bininstall; it just creates the python and other symbolic links.

# Install the interpreter by creating a symlink chain:
# $(PYTHON) -> python2 -> python$(VERSION))
# Also create equivalent chains for other installed files
bininstall: altbininstall
-if test -f $(DESTDIR)$(BINDIR)/$(PYTHON) -o -h $(DESTDIR)$(BINDIR)/$(PYTHON); \
then rm -f $(DESTDIR)$(BINDIR)/$(PYTHON); \
else true; \
fi
(cd $(DESTDIR)$(BINDIR); $(LN) -s python2$(EXE) $(PYTHON))
-rm -f $(DESTDIR)$(BINDIR)/python2$(EXE)
(cd $(DESTDIR)$(BINDIR); $(LN) -s python$(VERSION)$(EXE) python2$(EXE))
... (More links created)

And here’s maninstall, it just creates “unversioned” links to the Python manual pages.

# Install the unversioned manual pages
maninstall: altmaninstall
-rm -f $(DESTDIR)$(MANDIR)/man1/python2.1
(cd $(DESTDIR)$(MANDIR)/man1; $(LN) -s python$(VERSION).1 python2.1)
-rm -f $(DESTDIR)$(MANDIR)/man1/python.1
(cd $(DESTDIR)$(MANDIR)/man1; $(LN) -s python2.1 python.1)

TLDR: altinstall skips creating the python link and the manual pages links, install will hide the system binaries and manual pages.

1.1.2. 兼容性修正

1.1.2.1. Redhat/CentOS 系

一般在 /usr/bin/ 下放一個鏈接，鏈接到 /usr/local/bin/ 下面:

$ ln -s /usr/local/bin/pip /usr/bin/pip
$ ln -s /usr/local/bin/pip3 /usr/bin/pip3
$ ln -s /usr/local/bin/pip3.9 /usr/local/bin/pip3

1.1.2.2. Debian/Ubuntu 系

1.1.3. 快速虛擬化環境工具

• virtualenv
• venv

1.2. Step 1: Install Python Dependencies

Login to your CentOS 8 / CentOS 7 system as root or user with sudo privileges.

Then do system update

sudo yum -y install epel-release
sudo yum -y update

Reboot after the upgrade before you continue to install dependencies

sudo reboot

Install required software development tools required to build Python 3.9 on CentOS 8 / CentOS 7:

sudo yum groupinstall "Development Tools" -y
sudo yum install openssl-devel libffi-devel bzip2-devel -y

Confirm gcc is available:

$ gcc --version
gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

1.3. Step 2: Download latest Python 3.9 Archive

Ensure wget is installed:

sudo yum install wget -y

Use wget to download the latest Python 3.9 release.

wget https://www.python.org/ftp/python/3.9.10/Python-3.9.10.tgz

Extract the archive file using tar:

tar xvf Python-3.9.10.tgz

Switch to the directory created from the file extraction:

cd Python-3.9*/

1.4. Step 3: Install Python 3.9 on CentOS 8 / CentOS 7

Run the command below to configure Python installation.

./configure --enable-optimizations

Build Python 3.9 on CentOS 8 / CentOS 7:

sudo make altinstall # altinstall is important, DO NOT use `make install`.

Python 安裝時 make install 和 make altinstall 的區別: altinstall skips creating the python link and the manual pages links. altinstall 跳過創建 Python 鏈接和手冊頁鏈接的操作。如果使用 make install，在系統中將會有兩個不同版本的 Python 在 /usr/bin 目錄中，這將會導致很多問題。

Be patient as this takes quite some time depending on number of CPU cores in your system.

Check Python 3.9 installation on CentOS 8 / CentOS 7. Run below command to confirm successful installation of Python 3.9 on CentOS 8 / CentOS 7:

$ python3.9 --version
Python 3.9.10

Pip3.9 must have been installed as well:

$ pip3.9 --version
pip 21.2.4 from /usr/local/lib/python3.9/site-packages/pip (python 3.9)

Upgrade pip

$ /usr/local/bin/python3.9 -m pip install --upgrade pip
$ pip3.9 --version