了解一下 setV，它是一个轻量级的 Python 虚拟环境管理器，是 virtualenvwrapper 的替代产品。

这一年多来，我的 bash_scripts 项目中悄悄隐藏这 setV，但现在是时候该公开了。setV 是一个 Bash 函数，我可以用它代替 virtualenvwrapper。它提供了使你能够执行以下操作的基本功能：

• 默认使用 Python 3
• 创建一个新的虚拟环境
• 使用带有 -p（或 --python）的自定义 Python 路径来创建新的虚拟环境
• 删除现有的虚拟环境
• 列出所有现有的虚拟环境
• 使用制表符补全（以防你忘记虚拟环境名称）

安装 {#toc_1}

要安装 setV，请下载该脚本：

curl https://gitlab.com/psachin/setV/raw/master/install.sh

审核一下脚本，然后运行它：

sh ./install.sh

当安装 setV 时，安装脚本会要求你引入（source）一下 ~/.bashrc 或 ~/.bash_profile 的配置，根据你的喜好选择一个。

用法 {#toc_2}

基本的命令格式是 setv。

创建虚拟环境 {#toc_3}

setv --new rango  # setv -n rango
或使用定制的 Python 路径
setv --new --python /opt/python/python3 rango # setv -n -p /opt/python/python3 rango

激活已有的虚拟环境 {#toc_4}

setv VIRTUAL_ENVIRONMENT_NAME
示例
setv rango

列出所有的虚拟环境 {#toc_5}

setv --list
# 或
setv [TAB] [TAB]

删除虚拟环境 {#toc_6}

setv --delete rango

切换到另外一个虚拟环境 {#toc_7}

# 假设你现在在 'rango'，切换到 'tango'
setv tango

制表符补完 {#toc_8}

如果你不完全记得虚拟环境的名称，则 Bash 式的制表符补全也可以适用于虚拟环境名称。

参与其中 {#toc_9}

setV 在 GNU GPLv3下开源，欢迎贡献。要了解更多信息，请访问它的 GitLab 存储库中的 setV 的 README 的贡献部分。

setV 脚本 {#toc_10}

#!/usr/bin/env bash
# setV - A Lightweight Python virtual environment manager.
# Author: Sachin (psachin) <iclcoolster@gmail.com>
# Author's URL: https://psachin.gitlab.io/about
#
# License: GNU GPL v3, See LICENSE file
#
# Configure(Optional):
# Set `SETV_VIRTUAL_DIR_PATH` value to your virtual environments
# directory-path. By default it is set to '~/virtualenvs/'
#
# Usage:
# Manual install: Added below line to your .bashrc or any local rc script():
# ---
# source /path/to/virtual.sh
# ---
#
# Now you can 'activate' the virtual environment by typing
# $ setv <YOUR VIRTUAL ENVIRONMENT NAME>
#
# For example:
# $ setv rango
#
# or type:
# setv [TAB] [TAB]  (to list all virtual envs)
#
# To list all your virtual environments:
# $ setv --list
#
# To create new virtual environment:
# $ setv --new new_virtualenv_name
#
# To delete existing virtual environment:
# $ setv --delete existing_virtualenv_name
#
# To deactivate, type:
# $ deactivate
Path to virtual environment directory
SETV_VIRTUAL_DIR_PATH="$HOME/virtualenvs/"
Default python version to use. This decides whether to use virtualenv or python3 -m venv
SETV_PYTHON_VERSION=3  # Defaults to Python3
SETV_PY_PATH=$(which python${SETV_PYTHON_VERSION})
function setvcomplete()
{
Bash-autocompletion.
This ensures Tab-auto-completions work for virtual environment names.
local cmd="${1##*/}" # to handle command(s).
Not necessary as such. 'setv' is the only command
local word=${COMP_WORDS[COMP_CWORD]} # Words thats being completed
local xpat='${word}'                 # Filter pattern. Include
                                     # only words in variable '$names'
local names=$(ls -l &quot;${SETV_VIRTUAL_DIR_PATH}&quot; | egrep '^d' | awk -F &quot; &quot; '{print $NF}') # Virtual environment names
COMPREPLY=($(compgen -W &quot;$names&quot; -X &quot;$xpat&quot; -- &quot;$word&quot;)) # compgen generates the results

}
function setv_help() {
Echo help/usage message
echo "Usage: setv [OPTIONS] [NAME]"
echo Positional argument:
echo -e "NAME                       Activate virtual env."
echo Optional arguments:
echo -e "-l, --list                 List all Virtual Envs."
echo -e "-n, --new NAME             Create a new Python Virtual Env."
echo -e "-d, --delete NAME          Delete existing Python Virtual Env."
echo -e "-p, --python PATH          Python binary path."
}
function _setv_custom_python_path()
{
if [ -f "${1}" ];
then
if [ "expr $1 : '.*python\([2,3]\)'" = "3" ];
then
SETV_PYTHON_VERSION=3
else
SETV_PYTHON_VERSION=2
fi
SETV_PY_PATH=${1}
_setv_create $2
else
echo "Error: Path ${1} does not exist!"
fi
}
function _setv_create()
{
Creates new virtual environment if ran with -n|--new flag
if [ -z ${1} ];
then
echo "You need to pass virtual environment name"
setv_help
else
echo "Creating new virtual environment with the name: $1"
    if [ ${SETV_PYTHON_VERSION} -eq 3 ];
    then
        ${SETV_PY_PATH} -m venv ${SETV_VIRTUAL_DIR_PATH}${1}
    else
        virtualenv -p ${SETV_PY_PATH} ${SETV_VIRTUAL_DIR_PATH}${1}
    fi
echo &amp;quot;You can now activate the Python virtual environment by typing: setv ${1}&amp;quot;

fi

}
function _setv_delete()
{
Deletes virtual environment if ran with -d|--delete flag
TODO: Refactor
if [ -z ${1} ];
then
echo "You need to pass virtual environment name"
setv_help
else
if [ -d ${SETV_VIRTUAL_DIR_PATH}${1} ];
then
read -p "Really delete this virtual environment(Y/N)? " yes_no
case $yes_no in
Y|y) rm -rvf ${SETV_VIRTUAL_DIR_PATH}${1};;
N|n) echo "Leaving the virtual environment as it is.";;
*) echo "You need to enter either Y/y or N/n"
esac
else
echo "Error: No virtual environment found by the name: ${1}"
fi
fi
}
function _setv_list()
{
Lists all virtual environments if ran with -l|--list flag
echo -e "List of virtual environments you have under ${SETV_VIRTUAL_DIR_PATH}:\n"
for virt in $(ls -l "${SETV_VIRTUAL_DIR_PATH}" | egrep '^d' | awk -F " " '{print $NF}')
do
echo ${virt}
done
}
function setv() {
Main function
if [ $# -eq 0 ];
then
setv_help
elif [ $# -le 3 ];
then
case "${1}" in
-n|--new) _setv_create ${2};;
-d|--delete) _setv_delete ${2};;
-l|--list) _setv_list;;
*) if [ -d ${SETV_VIRTUAL_DIR_PATH}${1} ];
then
Activate the virtual environment
source ${SETV_VIRTUAL_DIR_PATH}${1}/bin/activate
else
Else throw an error message
echo "Sorry, you don't have any virtual environment with the name: ${1}"
setv_help
fi
;;
esac
elif [ $# -le 5 ];
then
case "${2}" in
-p|--python) _setv_custom_python_path ${3} ${4};;
*) setv_help;;
esac
fi
}
Calls bash-complete. The compgen command accepts most of the same
options that complete does but it generates results rather than just
storing the rules for future use.
complete -Fsetvcompletesetv

via: https://opensource.com/article/20/1/setv-bash-function

作者：Sachin Patil 选题：lujun9972 译者：wxy 校对：wxy

本文由 LCTT 原创编译，Linux中国 荣誉推出