Why are my imports no longer working?
You need to install it in in your environment(according to the comments you didn't), please try the following:
Settings -> Project: MyProjectName -> Project Interpreter
Then click on the green plus and choose your packages
I refactored my webapp and now my IDE pycharm marks some imports red. Why?
from wtforms import Form, TextField, validators, SelectField
My IDE marks the Form, TextField and the SelectField red as they cannot be imported. ("Unresolved reference"). What should I do if I need those classes in my project?