升级 Ubuntu 16.04 LTS 时出错 python-minimal 包错误

Question 1

经过几个小时的努力和数百次安装/卸载 Python 包，我似乎能够安装 Python 包，包括python-minimal。让我分享我的成功故事。

一开始，我甚至无法卸载 python-minimal。每次安装/卸载时都会出现我在问题中提到的错误。即使尝试过sudo apt-get -f install也没有任何收获。不知怎么的，我发现它只能与其他几个软件包一起卸载。以下命令，我用来完成删除python-minimal损坏和残留的软件包：
```
sudo apt-get autoremove libpython-stdlib libpython2.7-minimal libpython2.7-stdlib python-minimal python2.7 python2.7-minimal
```
这将删除所有 python 包和依赖 python 的软件。我知道这很极端，但相信我，我别无选择。
```
sudo apt-get remove --purge $(sudo dpkg -l | egrep "^(rc|iU)" | awk '{print $2}' | tr '\n' ' ')
```
如果有的话，去除其余的残留和破损的包装。

笔记：我复制了此步骤中被删除的软件包列表。我知道我会再次需要它！

接下来我搜索了所有安装python2.7的地方，并删除了所有文件和目录默认 python。我希望不用手动删除它们，但别无选择：

sudo find / -iname python2.7
/etc/python2.7
/usr/local/bin/python2.7
/usr/local/lib/python2.7
/usr/lib/python2.7
/usr/bin/python2.7.13/lib/python2.7
/usr/bin/python2.7.13/bin/python2.7
/usr/bin/python2.7.13/include/python2.7
/usr/bin/python2.7
/usr/include/x86_64-linux-gnu/python2.7
/usr/include/python2.7
/usr/share/doc/python2.7
/usr/share/binfmts/python2.7
/usr/share/lintian/overrides/python2.7
/proc/sys/fs/binfmt_misc/python2.7
/var/lib/binfmts/python2.7

我没有删除上面列出的所有文件/目录，只删除了默认版本：

sudo rm -rf /etc/python2.7 /usr/local/bin/python2.7 /usr/local/lib/python2.7 /usr/lib/python2.7

还有其他版本的 Python，没有造成任何问题。我相信搜索可能因用户而异，whereis python可以使用命令获取默认 Python 安装的路径。

接下来我安装python成功了：

sudo apt-get install python
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  libpython-stdlib libpython2.7-minimal libpython2.7-stdlib python-minimal python2.7 python2.7-minimal
Suggested packages:
  python-doc python-tk python2.7-doc
The following NEW packages will be installed:
  libpython-stdlib libpython2.7-minimal libpython2.7-stdlib python python-minimal python2.7 python2.7-minimal
0 upgraded, 7 newly installed, 0 to remove and 21 not upgraded.
Need to get 0 B/3,877 kB of archives.
After this operation, 16.6 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Selecting previously unselected package libpython2.7-minimal:amd64.
(Reading database ... 250996 files and directories currently installed.)
Preparing to unpack .../libpython2.7-minimal_2.7.12-1ubuntu0~16.04.3_amd64.deb ...
Unpacking libpython2.7-minimal:amd64 (2.7.12-1ubuntu0~16.04.3) ...
Selecting previously unselected package python2.7-minimal.
Preparing to unpack .../python2.7-minimal_2.7.12-1ubuntu0~16.04.3_amd64.deb ...
Unpacking python2.7-minimal (2.7.12-1ubuntu0~16.04.3) ...
Selecting previously unselected package python-minimal.
Preparing to unpack .../python-minimal_2.7.12-1~16.04_amd64.deb ...
Unpacking python-minimal (2.7.12-1~16.04) ...
Selecting previously unselected package libpython2.7-stdlib:amd64.
Preparing to unpack .../libpython2.7-stdlib_2.7.12-1ubuntu0~16.04.3_amd64.deb ...
Unpacking libpython2.7-stdlib:amd64 (2.7.12-1ubuntu0~16.04.3) ...
Selecting previously unselected package python2.7.
Preparing to unpack .../python2.7_2.7.12-1ubuntu0~16.04.3_amd64.deb ...
Unpacking python2.7 (2.7.12-1ubuntu0~16.04.3) ...
Selecting previously unselected package libpython-stdlib:amd64.
Preparing to unpack .../libpython-stdlib_2.7.12-1~16.04_amd64.deb ...
Unpacking libpython-stdlib:amd64 (2.7.12-1~16.04) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for bamfdaemon (0.5.3~bzr0+16.04.20180209-0ubuntu1) ...
Rebuilding /usr/share/applications/bamf-2.index...
Processing triggers for desktop-file-utils (0.22-1ubuntu5.1) ...
Processing triggers for gnome-menus (3.13.3-6ubuntu3.1) ...
Processing triggers for mime-support (3.59ubuntu1) ...
Setting up libpython2.7-minimal:amd64 (2.7.12-1ubuntu0~16.04.3) ...
Setting up python2.7-minimal (2.7.12-1ubuntu0~16.04.3) ...
Linking and byte-compiling packages for runtime python2.7...
Setting up python-minimal (2.7.12-1~16.04) ...
Selecting previously unselected package python.
(Reading database ... 251742 files and directories currently installed.)
Preparing to unpack .../python_2.7.12-1~16.04_amd64.deb ...
Unpacking python (2.7.12-1~16.04) ...
Processing triggers for doc-base (0.10.7) ...
Processing 1 added doc-base file...
Registering documents with scrollkeeper...
Processing triggers for man-db (2.7.5-1) ...
Setting up libpython2.7-stdlib:amd64 (2.7.12-1ubuntu0~16.04.3) ...
Setting up python2.7 (2.7.12-1ubuntu0~16.04.3) ...
Setting up libpython-stdlib:amd64 (2.7.12-1~16.04) ...
Setting up python (2.7.12-1~16.04) ...

笔记：这仅安装了非常必要且最少的 Python 包。您可能仍需要安装在第一步中卸载的所有其他 Python 包。

一些额外说明：

第二步删除了使用以下方式全局安装的第三方 Python 包点子。不幸的是，我没有这个列表，最终我的项目需要它们时遇到了一些麻烦。但这不是什么大问题，因为我的所有项目都有自己的 python requirements.txt 文件。但我仍然建议大家在开始第一步之前将 python 包保存在一个文件中。以下命令可以派上用场：

pip freeze > python_pip_packages.txt

我还必须删除 pip 文件和目录（类似于删除 python 默认文件和目录的方式）并重新安装 pip：

sudo apt-get install python-pip  # installing pip
sudo pip install --upgrade pip  # upgrading pip to latest version using pip itself
sudo pip install -r python_pip_packages.txt  # re-installing all 3rd party python packages which were removed in 2nd step.

希望其他人不会像我一样受苦:)

Answer