pip install(速度が遅いかダウンロードタイムアウト)豆弁源を使用

pip install xxx -i http://pypi.douban.com/simple/
次のように誤報すれば

  The repository located at pypi.douban.com is not a trusted or secure host and is being ignored. If this repository is available via HTTPS we recommend you use HTTPS instead, otherwise you may silence this warning and allow it anyway with '--trusted-host pypi.douban.com'.
  Could not find a version that satisfies the requirement opencv-python (from versions: )
No matching distribution found for opencv-python
The repository located at pypi.douban.com is not a trusted or secure host and is being ignored. If this repository is available via HTTPS we recommend you use HTTPS instead, otherwise you may silence this warning and allow it anyway with '--trusted-host pypi.douban.com'.

pip install xxx-iに変更http://pypi.douban.com/simple/--trusted-host pypi.douban.com