1.問題：Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/Library/Python/3.7/site-packages'
解決方案：
?sudo 所執(zhí)行的指令就好像是 root 親自執(zhí)行问慎。
sudo pip3 install opencv-python
2.讓系統(tǒng)默認(rèn)使用python3
(1).查看python3的安裝路徑
which python3?
(2).執(zhí)行命令?
vi ~/.bash_profile?
（3）? ?# 添加這一行??（引號中的路徑為自己電腦的路徑）
?alias python="/usr/local/bin/python3"
3.ERROR: Could not find a version that satisfies the requirement cv2 (from versions: none)
ERROR: No matching distribution found for cv2
解決方案：
