目前,我使用的是Ubuntu 19操作系统,默认安装了Python 3.7.5版本。但是我需要将其降级为3.6.5版本。
修改后:
我正在使用虚拟环境。
目前,我使用的是Ubuntu 19操作系统,默认安装了Python 3.7.5版本。但是我需要将其降级为3.6.5版本。
修改后:
我正在使用虚拟环境。
以下内容讲解从3.6.7升级到3.7.0的过程,但您可以使用相同的步骤进行降级。除非您确切知道自己在做什么,否则不应更改系统python。
$ pyenv
pyenv 1.2.14
Usage: pyenv <command> [<args>]
Some useful pyenv commands are:
commands List all available pyenv commands
activate Activate virtual environment
commands List all available pyenv commands
deactivate Deactivate virtual environment
doctor Verify pyenv installation and deevlopment tools to build pythons.
exec Run an executable with the selected Python version
global Set or show the global Python version
help Display help for a command
hooks List hook scripts for a given pyenv command
init Configure the shell environment for pyenv
install Install a Python version using python-build
local Set or show the local application-specific Python version
prefix Display prefix for a Python version
rehash Rehash pyenv shims (run this after installing executables)
root Display the root directory where versions and shims are kept
shell Set or show the shell-specific Python version
shims List existing pyenv shims
uninstall Uninstall a specific Python version
--version Display the version of pyenv
version Show the current Python version and its origin
version-file Detect the file that sets the current pyenv version
version-name Show the current Python version
version-origin Explain how the current Python version is set
versions List all Python versions available to pyenv
virtualenv Create a Python virtualenv using the pyenv-virtualenv plugin
virtualenv-delete Uninstall a specific Python virtualenv
virtualenv-init Configure the shell environment for pyenv-virtualenv
virtualenv-prefix Display real_prefix for a Python virtualenv version
virtualenvs List all Python virtualenvs found in `$PYENV_ROOT/versions/*'.
whence List all Python versions that contain the given executable
which Display the full path to an executable
See `pyenv help <command>' for information on a specific command.
For full documentation, see: https://github.com/pyenv/pyenv#readme
$ pyenv versions
system
* 3.6.7 (set by /home/taarimalta/.pyenv/version)
$ pyenv install 3.7.0
Installing Python-3.7.0...
WARNING: The Python bz2 extension was not compiled. Missing the bzip2 lib?
WARNING: The Python readline extension was not compiled. Missing the GNU readline lib?
WARNING: The Python sqlite3 extension was not compiled. Missing the SQLite3 lib?
Installed Python-3.7.0 to /home/taarimalta/.pyenv/versions/3.7.0
如果您在_ctypes安装时遇到问题,需安装libffi-dev库
$ pyenv versions
system
* 3.6.7 (set by /home/taarimalta/.pyenv/version)
3.7.0
$ pyenv local 3.7.0
$ pyenv versions
system
3.6.7
* 3.7.0 (set by /home/taarimalta/.python-version)
$ python
Python 3.7.0 (default, Jan 1 2020, 10:52:57)
[GCC 9.2.1 20191008] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
cd ../project2
pyenv versions
system
* 3.6.7 (set by /home/taarimalta/.pyenv/version)
3.7.0
根据您本地设置的Python版本,此处的Python版本可能会有所不同。
这将为用户全局设置Python版本。
pyenv global 3.7.0
请注意,pyenv通过添加一个.python-version文件来设置本地版本。$ pyenv local 3.7.0
$ cat .python-version
3.7.0
注意,pyenv 通过查看 ~/.pyenv/version
文件来确定全局版本。cat ~/.pyenv/version
3.8.2
which python3
命令来查看。 - taari或者你可以轻松地创建一个虚拟环境。
假设你的系统安装了 Python3.8(或更高版本),但是对于特定任务,你需要Python 3.7(或更低版本)。最好的方法是使用 Python 3.7(或任何3.x,根据您想要的版本更改下面的命令。以下是使用 Python 3.7 实现虚拟环境的示例)创建虚拟环境。
步骤:(2022年8月检查)
安装Python 3.7及其虚拟环境包:从预编译的Ubuntu deb软件包仓库中安装它。
$ sudo apt update
$ sudo apt install software-properties-common
$ sudo add-apt-repository ppa:deadsnakes/ppa
当提示时,请按ENTER键继续。
sudo apt install python3.6
你还可以使用virtualenv来使用不同的Python环境。
如果你输入python并按两次Tab键,你可能会看到许多可用的Python版本。我之所以这样说,是因为当我键入时
python3.6 -V
我有
Python 3.6.9
可用。我的Python别名是3.7.5
当你输入Python时,你可能指的是在.bashrc中定义的别名