This is the re-implemented code following The Flask Mega-Tutorial, which is very useful for beginners of flask, datebases or web developers.
flaskfor Python HTTP serverflask_wtffor flask formsflask_sqlalchemyfor SQL and databasesflask_migratefor database upgrade
export FLASK_APP=./microblog.py
flask runexport FLASK_APP=./microblog.py
flask db migrate
flask db upgradepython -m smtpd -n -c DebuggingServer localhost:8025Then set up temporary server and start flask
export MAIL_SERVER=localhost
export MAIL_PORT=8025
export FLASK_APP=./microblog.py
flask runpython tests.py