python - 升级python而不破坏yum

Question

我最近通过从源代码编译在 CentOS 机器上安装了 Python 2.7.3。 Python 2.7.3 安装在/opt/python2.7 中，当我安装它时，我只是将/usr/bin/python 更改为指向新版本。这显然是错误的，因为当我这样做时它打破了百胜。我会得到以下内容。

There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   No module named yum

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.3 (default, May 15 2012, 17:45:42) 
[GCC 4.4.4 20100726 (Red Hat 4.4.4-13)]

If you cannot solve this problem yourself, please go to 
the yum faq at:
  http://yum.baseurl.org/wiki/Faq

我将/usr/bin/python 更改为指向 python 2.6.6，但现在 2.6.6 是 python 的默认版本。知道如何解决这个问题吗？

Answer 1

我写了一个quick guide关于如何在 CentOS 6 和 CentOS 7 上安装最新版本的 Python 2 和 Python 3。目前涵盖 Python 2.7.13 和 Python 3.6.0:

# Start by making sure your system is up-to-date:
yum update
# Compilers and related tools:
yum groupinstall -y "development tools"
# Libraries needed during compilation to enable all features of Python:
yum install -y zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel expat-devel
# If you are on a clean "minimal" install of CentOS you also need the wget tool:
yum install -y wget

接下来的步骤取决于您安装的 Python 版本。

对于 Python 2.7.14:

wget http://python.org/ftp/python/2.7.14/Python-2.7.14.tar.xz
tar xf Python-2.7.14.tar.xz
cd Python-2.7.14
./configure --prefix=/usr/local --enable-unicode=ucs4 --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
make && make altinstall

# Strip the Python 2.7 binary:
strip /usr/local/lib/libpython2.7.so.1.0

对于 Python 3.6.3:

wget http://python.org/ftp/python/3.6.3/Python-3.6.3.tar.xz
tar xf Python-3.6.3.tar.xz
cd Python-3.6.3
./configure --prefix=/usr/local --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
make && make altinstall

# Strip the Python 3.6 binary:
strip /usr/local/lib/libpython3.6m.so.1.0

要安装 Pip:

# First get the script:
wget https://bootstrap.pypa.io/get-pip.py

# Then execute it using Python 2.7 and/or Python 3.6:
python2.7 get-pip.py
python3.6 get-pip.py

# With pip installed you can now do things like this:
pip2.7 install [packagename]
pip2.7 install --upgrade [packagename]
pip2.7 uninstall [packagename]

您不应该更改 Python 的系统版本，因为它会破坏系统(正如您所发现的)。只要您不理会原始系统版本，安装其他版本就可以正常工作。这可以通过在运行 configure 时使用自定义前缀(例如 /usr/local)和使用 make altinstall(而不是普通的 make install) 安装您的 Python 版本时。

只要您记得输入包含版本号的全名(例如“python2.7”或“pip2.7”)，拥有多个可用的 Python 版本通常不是什么大问题。如果您从 virtualenv 完成所有 Python 工作，则版本控制会为您处理，因此请确保您安装并使用 virtualenv!