a、创建Python项目，其结构如下：

b、激活虚拟环境

启动DOS窗口—>进入“Scripts”目录，这里为D:\workspace\prj_python_1\venv\Scripts—>执行activate激活虚拟环境，如下所示：

Microsoft Windows [版本 10.0.18363.535]
(c) 2019 Microsoft Corporation。保留所有权利。

C:\Users\GaoHuanjie>cd /d D:\workspace\prj_python_1\venv\Scripts

D:\workspace\prj_python_1\venv\Scripts>activate

(venv) D:\workspace\prj_python_1\venv\Scripts>

注意：activate命令执行后，命令执行路径前面会自动添加“(venv) ”。

c、下载Python包

虚拟环境激活后，再使用pip install命令安装Python包，Python包将被保存至该虚拟环境下“Lib\site-packages”文件夹内，而不会保存到Python根目录下的相关文件夹中，操作如下：

Microsoft Windows [版本 10.0.18363.535]
(c) 2019 Microsoft Corporation。保留所有权利。

C:\Users\GaoHuanjie>cd /d D:\workspace\prj_python_1\venv\Scripts

D:\workspace\prj_python_1\venv\Scripts>activate

(venv) D:\workspace\prj_python_1\venv\Scripts>pip install -i https://mirrors.aliyun.com/pypi/simple/ pymysql==1.1.0rc1
Looking in indexes: https://mirrors.aliyun.com/pypi/simple/
Collecting pymysql==1.1.0rc1
...省略...
Installing collected packages: pymysql
Successfully installed pymysql-1.1.0rc1

[notice] A new release of pip is available: 23.2.1 -> 23.3.2
[notice] To update, run: python.exe -m pip install --upgrade pip

(venv) D:\workspace\prj_python_1\venv\Scripts>

d、退出虚拟环境

若退出该虚拟环境，直接执行deactivate.bat命令即可，如下所示：

Microsoft Windows [版本 10.0.18363.535]
(c) 2019 Microsoft Corporation。保留所有权利。

C:\Users\GaoHuanjie>cd /d D:\workspace\prj_python_1\venv\Scripts

D:\workspace\prj_python_1\venv\Scripts>activate

(venv) D:\workspace\prj_python_1\venv\Scripts>pip install -i https://mirrors.aliyun.com/pypi/simple/ pymysql==1.1.0rc1
Looking in indexes: https://mirrors.aliyun.com/pypi/simple/
Collecting pymysql==1.1.0rc1
...省略...
Installing collected packages: pymysql
Successfully installed pymysql-1.1.0rc1

[notice] A new release of pip is available: 23.2.1 -> 23.3.2
[notice] To update, run: python.exe -m pip install --upgrade pip

(venv) D:\workspace\prj_python_1\venv\Scripts>deactivate.bat
D:\workspace\prj_python_1\venv\Scripts>