python安装pillow时出错不知道是什么问题

Installing collected packages: pillow
ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
pyautogui 0.9.33 requires pymsgbox, which is not installed.
pyautogui 0.9.33 requires PyTweening>=1.0.1, which is not installed.
Successfully installed pillow-8.4.0
WARNING: You are using pip version 21.2.3; however, version 21.3.1 is available.
You should consider upgrading via the 'C:\Users\97817\AppData\Local\Programs\Python\Python39\python.exe -m pip install --upgrade pip' command.

看日志，很明显

pyautogui 0.9.33 requires pymsgbox, which is not installed.
pyautogui 0.9.33 requires PyTweening>=1.0.1, which is not installed.