How to do it...

We can have a default setting base class, and other classes can inherit that base class and override or add deployment-specific configuration variables to it, as shown in the following example:

class BaseConfig(object): 
    'Base config class' 
    SECRET_KEY = 'A random secret key' 
    DEBUG = True 
    TESTING = False 
    NEW_CONFIG_VARIABLE = 'my value' 
 
class ProductionConfig(BaseConfig): 
    'Production specific config' 
    DEBUG = False 
    SECRET_KEY = open('/path/to/secret/file').read() 
 
class StagingConfig(BaseConfig): 
    'Staging specific config' 
    DEBUG = True 
 
class DevelopmentConfig(BaseConfig): 
    'Development environment specific config' 
    DEBUG = True 
    TESTING = True 
 
    SECRET_KEY = 'Another random secret key'