pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.

用pip安装tornado库：

python -m pip install tornado

出现问题一： Could not fetch URL https://pypi.org/simple/twisted/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host=‘pypi.org‘, port=443): Max retries exceeded with url: /simple/twisted/ (Caused by SSLError("Can‘t connect to HTTPS URL because the SSL module is not available.")) - skipping

 解决办法：python -m pip install tornado --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org

即在库名后＋  --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org

出现问题二：pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host=‘files.pythonhosted.org‘, port=443): Read timed out.

解决办法：python -m pip install --default-timeout=100 tornado  --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org

pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.

原文：https://www.cnblogs.com/qihuang94/p/12115639.html