Setup project folder:
$ mkdir flask-rest-api; cd flask-rest-api
$ python3 -m venv venv
$ source venv/bin/activate
Check your env, make sure it is the version that you should run on:
$ python -V; pip -V
Install flask and packages:
$ pip install flask flask-sqlalchemy marshmallow psycopg2-binary
Generate freeze requirement text file:
$ pip3 freeze > requirements.txt
Create your app.py file
$ touch app.py
Use any code editor to work on your project.