how can i access a global variable in a python inner class

Question

Am new to Python. I am working on a project using Peewee ORM and Bottle.

My models.py file defines my models. My "db" variable is defined in my main file(index.py). I would like to access that same "db" instance using a global in the BaseModel Meta inner class below.

from peewee import *
import settings

class BaseModel(Model):
    global db
    class Meta:
        global db
        database = db

class Account(BaseModel):
    created_ip = CharField(null=True)
    created_on = DateTimeField()

I get the error below when i try to run the code

Traceback (most recent call last):
  File "index.py", line 11, in <module>
    from models import Account, Crawl, Site, Url
  File "/api/models.py", line 4, in <module>
    class BaseModel(Model):
  File "/api/models.py", line 7, in BaseModel
    class Meta:
  File "/api/models.py", line 9, in Meta
    database = db
NameError: name 'db' is not defined

Can i access the global "db" in the inner class, is there an easier way to use the global "db" instance in another file?

Thank you

Answer 1

Don't define your db database instance inside the main file. Keep it with your models in the models.py. And, according to the documentation, it is recommended to have a base model that would have the database "meta" attribute defined:

db = SqliteDatabase('my_app.db')

class BaseModel(Model):
    class Meta:
        database = db

class User(BaseModel):
    username = CharField()