pip install安装软件包报错：Requirement already satisfied

报错信息：

C:\Users\SUN>pip install pygame
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: pygame in c:\users\sun\appdata\roaming\python\python38\site-packages (2.1.2)

原因分析：
需要指定路径

解决方案：
使用 pip install --target=安装路径
如：pip install --target=c:\users\sun\appdata\roaming\python\python38\site-packages pygame

注意：--target=后紧跟安装路径无需空格

执行结果：

C:\Users\SUN>pip install --target=c:\users\sun\appdata\roaming\python\python38\site-packages pygame
Collecting pygame
Using cached pygame-2.1.2-cp38-cp38-win_amd64.whl (8.4 MB)
Installing collected packages: pygame
Successfully installed pygame-2.1.2

可使用 pip list 查看是否成功安装