今天在使用brew安裝Python的時候出現這個錯誤，翻譯過來大概意思是“你當前用戶沒有下列目錄的寫權限”
如下
Error: The following directories are not writable by your user:
/usr/local/lib/python3.7/site-packages
You should change the ownership of these directories to your user.
sudo chown -R $(whoami) /usr/local/lib/python3.7/site-packages
And make sure that your user has write permission.
chmod u+w /usr/local/lib/python3.7/site-packages
然後在網上百度，看到好多都是修改/usr/local/bin和/usr/local/share文件夾的權限，
可是，這兩個文件夾我當前用戶都有寫權限
但還是抱着試一試的心態照着做了，可是，該報錯還是報錯
如下例（爲了避免一些不必要的麻煩就對一些內容隱藏）
照着做了後，也無法安裝，然後仔細看報錯信息，
You should change the ownership of these directories to your user.
sudo chown -R $(whoami) /usr/local/lib/python3.7/site-packages
And make sure that your user has write permission.
chmod u+w /usr/local/lib/python3.7/site-packages
You should change the ownership of these directories to your user.
你應該修改這些目錄的所有權爲你當前用戶
And make sure that your user has write permission.
並且確保你當前用戶具有寫權限
寫的明明白白，並且還附上修改語句，爲什麼不仔細看錯誤提示？爲什麼？爲什麼？爲什麼？（這裏要加粗警示）
然後直接使用給的兩條語句，修改/usr/local/lib/python3.7/site-packages的所有權和權限，安裝Python，成功
