Ubuntu 16.04下如何彻底卸载Python 2.7.12并干净安装2.7.10？

Hey there, let's work through this properly—Ubuntu 16.04 leans heavily on Python 2.7 for core system tools, so we can't just uninstall the existing version outright without breaking things. Here's a safe, clean way to fully replace Python 2.7.12 with 2.7.10:

1. 安装编译依赖 #

Since we're building Python from source, first install all the required packages to avoid compilation errors:

• Update your package list:

  sudo apt update
  

• Install build dependencies:

  sudo apt install build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev
  

2. 获取并解压Python 2.7.10源码 #

• Download the Python 2.7.10 source tarball from the official Python repository, then save it to your working directory.
• Extract the tarball:

  tar xzf Python-2.7.10.tgz
  

• Move into the extracted directory:

  cd Python-2.7.10
  

3. 配置编译参数 #

We'll configure the build to install directly to /usr (the system's default Python path) to replace the existing version. The flags ensure shared libraries work correctly:

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

4. 编译并安装 #

• Compile the source code (use -j$(nproc) to use all your CPU cores for faster compilation):

  make -j$(nproc)
  

• Important: Back up the original Python binary first, just in case something goes wrong:

  sudo cp /usr/bin/python /usr/bin/python.bak
  

• Install the compiled Python version. We use make install here to overwrite the system's Python 2.7 files:

  sudo make install
  

5. 验证安装 #

Check that the replacement worked by verifying the Python version:

python --version
python2 --version

Both should output Python 2.7.10.

6. 修复pip（如果需要） #

If your pip installation breaks after the upgrade, get the get-pip.py script compatible with Python 2.7, then run:

sudo python get-pip.py

关键注意事项 #

• System stability risk: Replacing the system's default Python can cause issues with tools like apt that depend on specific Python versions. Always back up important data before proceeding, and test this in a non-production environment first if possible.
• Rollback option: If you run into system errors, you can temporarily revert to the original version with:

  sudo ln -sf /usr/bin/python.bak /usr/bin/python
  

内容的提问来源于stack exchange，提问作者Pedro Gordo