Create project skeleton.

.flaskenv

+FLASK_APP=opaque.py
+FLASK_ENV=development

.gitignore

+__pycache__
+venv

app/__init__.py

+from flask import Flask
+
+
+def create_app():
+    app = Flask(__name__)
+
+    return app

config.py

+import os
+
+
+class Config:
+    SECRET_KEY = os.environ.get('SECRET_KEY') or 'hard to guess string'

opaque.py

+from app import create_app
+
+
+app = create_app

requirements.txt

+Flask==1.0.3
+python-dotenv==0.10.3