run flask in debug mode code example

Example 1: flask debug

$ export FLASK_ENV=development
$ flask run

Example 2: flask how to run app

$ export FLASK_APP=hello.py
$ python -m flask run
 * Running on http://127.0.0.1:5000/

Example 3: flask debug

app.run(debug=True)

Example 4: how to set debug mode on in flask

set "FLASK_DEBUG=1" in .flaskenv file of your project.