lazy-env-configurator 0.1.0

Dynamic Config Class Creation using Environment Variables

LAZY_ENV_CONFIGURATOR

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A utility library for Dynamic Config class generation. Now no more repeated boilerplate code...

Before lazy_env_configurator, config classes used to be created as below.

    class BaseConfig:
        APP = os.environ.get("APP")
        APP_ENV = os.environ.get("APP_ENV")

        # authentication related configuration
        # DB Credentials
        DB_USERNAME = os.environ.get("DB_USERNAME")
        DB_PASSWORD = os.environ.get("DB_PASSWORD")
        DB_HOST = os.environ.get("DB_HOST")
        DB_PORT = os.environ.get("DB_PORT")
        DB_NAME = os.environ.get("DB_NAME")
        DB_DRIVER = os.environ.get("DB_DRIVER")

This use to require a lot of boiler plate and redundant code With lazy_env_configurator this can be reduced to below:

from lazy_env_configurator import BaseEnv, BaseConfig as Config_
class BaseConfig(BaseEnv):
    class Config(Config_):
        envs = ('APP',
        'APP_ENV',
        'DB_USERNAME',
        'DB_PASSWORD',
        'DB_PASSWORD',
        'DB_HOST',
        # defaults
        ('DB_PORT',3306),
        'DB_NAME',
        'DB_DRIVER'
        )

Benefits of using lazy_env_configurator over Normal classes

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• Low memory footprint.
• Lazily evaluates environment variable and only loads them when used.
• Once loaded, env variables are cached.
• Get defaults populated, in case of missing env variables.
• env attributes can be overridden easily.
• classes expose instance attribute preventing need to initialization and making it behave singleton.
• Loads .env files by default so you only need to focus on essentials.

How to use

Let us refer below example:

from lazy_env_configurator import BaseEnv, BaseConfig as Config_
class BaseConfig(BaseEnv):
    class Config(Config_):
        envs = ('APP',
        'APP_ENV',
        'DB_USERNAME',
        'DB_PASSWORD',
        'DB_PASSWORD',
        'DB_HOST',
        # defaults
        ('DB_PORT',3306),
        'DB_NAME',
        'DB_DRIVER'
        )

We can now use BaseConfig class create as below.

>>>BaseConfig.instance.APP

Every class, subclassed from BaseEnv would expose .instance attribute which will be instance of the subclass. This instance can be used to access all the attributes on the class.

For simplicity, metaclass pre-initialises created class, so to make it behave as singleton.

How this works ?

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lazy_env_configurator uses descriptors under the hood to dynamically populate env variables as attributes, thus making them available on demand, Lazily.