Skip to main content

Lazy environment variable configuration of declarative style.

Project description


Decoupled and lazy library to get settings from an environment variables.


Environment variables are the most common way to configure projects, based on Docker, hosted on clouds, e.t.c. In the end, it is a secure and simple way. So grab variables from an environment is the only feature of the package.

The first issue that becomes obvious at the simplest approach for getting environment variables is attempting to get the environment variables too early. For example, an app is initialized by tests, and you need different values for the settings at different tests. But if the values obtained in this way:

import os

VAR_A = os.environ['VAR_A']

from . import *

def a():

from . import module_a

class Test(unittest.TestCase):
    @mock.patch('os', 'environ', {"VAR_A": 1})
    def test_a(self, env):

The values are already loaded to the memory. Therefore mock will not work. And the saddest part that this issue is not solved in most of the advanced configuration libraries. So this is the first issue solved here by Buddy Config.


pip install buddy_config

Getting started

Buddy Config aims to be as declarative as possible.

import buddy_config

class MyConf(metaclass=buddy_config.Config):

This is a minimum of declaration that you need to have a setting. Let's pale it out. The name of a class attribute is the name of the setting, exactly how you suppose to call it. A string at position 0 of the following tuple is a name of an environment variable that you will retrieve from the environment. And the type class at position 1 of the tuple is the type value after it is retrieved from the environment. Both values are required.

To use the config, you need to instantiate it:

my_conf = MyConfig()

The value is not going to be retrieved until you actually get the attribute from the config.


Also it is not cached.


Defaults are flexible and could be different per instance of the config.

my_conf_a = MyConfig(NAME_OF_A_SETTING_A=1)
my_conf_b = MyConfig(NAME_OF_A_SETTING_A=2)


Moreover, you can add pre-processing of retrieved values.

class MyConf(metaclass=Config):

The optional items of the tuple are pre-processors. A pre-processor is a callable that must return a value of int, float, string, or bytes value.

If you need to create a combined setting using values from environment variables, no problem, buddy config can do that:

class MyConf(metaclass=Config):
        lambda self: int(self.NAME_OF_A_SETTING_A) + self.NAME_OF_A_SETTING_B

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

buddy-config-0.1.7.tar.gz (4.5 kB view hashes)

Uploaded source

Built Distribution

buddy_config-0.1.7-py3-none-any.whl (16.9 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page