Skip to main content

Configuration with typed env vars

Project description

cabina

Codecov PyPI PyPI - Downloads Python Version

Installation

pip3 install cabina

Usage

import cabina
from cabina import computed, env


class Config(cabina.Config):
    class Main(cabina.Section):
        API_HOST: str = env.str("API_HOST", default="localhost")
        API_PORT: int = env.int("API_PORT", default=8080)

        @computed
        def API_URL(cls) -> str:
            return f"http://{cls.API_HOST}:{cls.API_PORT}"
assert Config.Main.API_URL == "http://localhost:8080"
assert Config["Main"]["API_URL"] == "http://localhost:8080"

print

print(Config)
# class <Config>:
#     class <Main>:
#         API_HOST = 'localhost'
#         API_PORT = 8080
#         API_URL = 'http://localhost:8080'

Recipes

Root Section

export API_HOST=localhost;
export API_PORT=8080;
import cabina
from cabina import env


class Config(cabina.Config, cabina.Section):  # <- inherited from cabina.Section
    API_HOST = env.str("API_HOST")
    API_PORT = env.int("API_PORT")


assert Config.API_HOST == "localhost"
assert Config.API_PORT == 8080

Computed Values

export API_HOST=localhost;
export API_PORT=8080;
import cabina
from cabina import computed, env


class Config(cabina.Config, cabina.Section):
    API_HOST: str = env.str("API_HOST")
    API_PORT: int = env.int("API_PORT")

    @computed
    def API_URL(cls) -> str:
        return f"http://{cls.API_HOST}:{cls.API_PORT}"


assert Config.API_URL == "http://localhost:8080"

Default Values

export API_HOST=127.0.0.1;
import cabina
from cabina import env


class Config(cabina.Config, cabina.Section):
    API_HOST = env.str("API_HOST", default="localhost")  # <- default arg
    API_PORT = env.int("API_PORT", default=8080)


assert Config.API_HOST == "127.0.0.1"
assert Config.API_PORT == 8080

Raw Values

export DEBUG= yes;
#            ^ extra space
import cabina
from cabina import env


class Config(cabina.Config, cabina.Section):
    DEBUG_RAW = env.raw("DEBUG")  # <- alias to env("DEBUG")
    DEBUG_STR = env.str("DEBUG")


assert Config.DEBUG_RAW == ""  # True
assert Config.DEBUG_STR == "yes"  # Error

Custom Parsers

export HTTP_TIMEOUT=10s;
import cabina
from cabina import env
from pytimeparse import parse as parse_duration  # <- external package


class Config(cabina.Config, cabina.Section):
    HTTP_TIMEOUT: int = env("HTTP_TIMEOUT", parser=parse_duration)


assert Config.HTTP_TIMEOUT == 10

JSON Parser

export IMAGE_SETTINGS='{"AllowedContentTypes": ["image/png", "image/jpeg"]}';
import json

import cabina
from cabina import env


class Config(cabina.Config, cabina.Section):
    IMAGE_SETTINGS = env("IMAGE_SETTINGS", parser=json.loads)  # <- json.loads


assert Config.IMAGE_SETTINGS == {
    'AllowedContentTypes': ['image/png', 'image/jpeg']
}

Lazy Env

export DEBUG=yes;
export API_PORT=80a;  # <- extra "a"
import cabina
from cabina import lazy_env


class Config(cabina.Config, cabina.Section):
    DEBUG = lazy_env.bool("DEBUG")
    API_HOST = lazy_env.str("API_HOST")  # the actual value is retrieved on first access
    API_PORT = lazy_env.int("API_PORT")


Config.prefetch()  # <- prefetch() accesses all variables

# ConfigEnvError: Failed to prefetch:
# - Config.API_HOST: 'API_HOST' does not exist
# - Config.API_PORT: Failed to parse '80a' as int

Env Vars Prefix

export APP_HOST=localhost;
export APP_PORT=8080;
import cabina

env = cabina.Environment(prefix="APP_")


class Config(cabina.Config, cabina.Section):
    API_HOST = env.str("HOST")  # <- No "APP_" prefix
    API_PORT = env.int("PORT")


assert Config.API_HOST == "localhost"
assert Config.API_PORT == 8080

Inheritance

import cabina


class Config(cabina.Config, cabina.Section):
    DEBUG = False

    class Api(cabina.Section):
        API_HOST = "app.dev"
        API_PORT = 5000


class ConfigLocal(Config):
    DEBUG = True

    class Api(Config.Api):
        API_HOST = "localhost"


assert ConfigLocal.DEBUG is True
assert ConfigLocal.Api.API_HOST == "localhost"
assert ConfigLocal.Api.API_PORT == 5000

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

cabina-1.0.0.tar.gz (17.1 kB view hashes)

Uploaded Source

Built Distribution

cabina-1.0.0-py3-none-any.whl (13.6 kB view hashes)

Uploaded Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page