pip install python-decouple

   DEBUG=True
   SECRET_KEY=mysecretkey
   DATABASE_URL=postgres://user:password@localhost:5432/mydatabase
   

   from decouple import config

   DEBUG = config('DEBUG', default=False, cast=bool)
   SECRET_KEY = config('SECRET_KEY')
   DATABASE_URL = config('DATABASE_URL')
   

   DEBUG=True
   SECRET_KEY=mysecretkey
   DATABASE_URL=sqlite:///mydatabase.db
   

   from flask import Flask
   from decouple import config

   app = Flask(__name__)

   app.config['DEBUG'] = config('DEBUG', default=False, cast=bool)
   app.config['SECRET_KEY'] = config('SECRET_KEY')
   app.config['SQLALCHEMY_DATABASE_URI'] = config('DATABASE_URL')

   @app.route('/')
   def home():
       return "Hello, World!"

   if __name__ == '__main__':
       app.run()
   

git commit -m ":bug: fix a bug"

app1/models.py
class ModelOne(models.Model):
    ...

app2/models.py
class ModelTwo(models.Model):
   model_one = models.ForeignKey("app1.ModelOne")

#### blog_app/models/__init__.py
from .comment import Comment 
from .post import Post
#### blog_app/models/comment.py 
class Comment(models.Model):
    # comment fields 
#### blog_app/models/post.py

from django.db import connection
from django.db import reset_queries 
def database_debug(func):
    def inner_func(*args, **kwargs): 
        reset_queries()
        results = func(*args, **kwargs) 
        query_info = connection.queries
        print(f'function_name: {func.__name__}') 
        print(f'query_count: {len(query_info)}')
        queries = [f'{ query["sql"]}\n' for query in query_info] 
        print(f'queries: \n{"".join(queries)}')
        return results 
    return inner_func

@database_debug
def regular_query(): 
    blogs = models.Blog.objects.all()
    return [blog.author.name for blog in blogs] 

## OUTPUT
function_name: regular_query
query_count: 4
queries:
SELECT "blog_blog"."id", "blog_blog"."noscript",
"blog_blog"."content", "blog_blog"."author_id", 
"blog_blog"."created_at", "blog_blog"."updated_at" FROM
"blog_blog"
SELECT "author_author"."id", "author_author"."name",
"author_author"."email", "author_author"."bio" FROM 
"author_author" WHERE "author_author"."id" = 1 LIMIT 21
SELECT "author_author"."id", "author_author"."name", 
"author_author"."email", "author_author"."bio" FROM
"author_author" WHERE "author_author"."id" = 2 LIMIT 21
SELECT "author_author"."id", "author_author"."name",
"author_author"."email", "author_author"."bio" FROM 
"author_author" WHERE "author_author"."id" = 2 LIMIT 21

CREATE TABLE order (
    id INT PRIMARY KEY AUTO_INCREMENT,
    ...
    plan_id INT NULL,
    product_id INT NULL,
)