Could not find a version that satisfies the requirement Werkzeug>=0.15 (from flask) (from versions: none)的解决

Enter pip install flask encountered an error in dos command window

error:

ERROR: Could not find a version that satisfies the requirement Werkzeug>=0.15 (from flask) (from versions: none)
ERROR: No matching distribution found for Werkzeug>=0.15 (from flask)

 

 

Solution

　　1. pip --trusted-host pypi.python.org install installation package name (Flask)

 

　　2. If there is not a mirror site

　　pip install the installation package name -i http://pypi.doubanio.com/simple/ --trusted-host pypi.doubanio.com