config.py

import os

basedir = os.path.abspath(os.path.dirname(__file__))

class Config:
    SECRET_KEY = os.environ.get('SECRET_KEY') or 'twas brillig and the slithy toves'
    @staticmethod
    def init_app(app):
        pass

class DevelopmentConfig(Config):
    DEBUG = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('DEV_DATABASE_URL') or 'sqlite:///' + os.path.join(basedir, 'resumes.db')

class TestingConfig(Config):
    TESTING = True
    SQLALCHEMY_DATABASE_URI = 'sqlite:resumes.db'

class ProductionConfig(Config):
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or 'sqlite:///' + os.path.join(basedir, 'resumes.db')

config = {
    'development': DevelopmentConfig,
    'testing': TestingConfig,
    'production': ProductionConfig,
    'default': DevelopmentConfig
}