Environment variable parsing for Django projects using dotenv

env.py

# Simple and explicit environment variable parsing for Django projects
# Uses the "dotenv" package to automatically load .env file
# See https://apibakery.com/blog/django-settings-howto/
#
# Written by Senko Rasic <senko@apibakery.com>
# Released into Public Domain

import os
from dotenv import load_dotenv

load_dotenv()

__all__ = [
    "BASE_DIR", "ABS_PATH",
    "ENV_BOOL", "ENV_STR", "ENV_INT",
    "ENV_DEC", "ENV_LIST",
]

# Assume we're in a subdirectory of project root (eg. "settings/env.py")
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


def ABS_PATH(*args):
    """Given a relative path within project, returns the absolute path"""
    return os.path.join(BASE_DIR, *args)


def ENV_BOOL(name, default=False):
    """
    Parses env variable as a boolean and returns it.
    
    If not set or can't be parsed, returns the default value,
    or False if default isn't given.
    """
    if name not in os.environ:
        return default
    if os.environ[name].lower() in ["true", "yes", "1"]:
        return True
    elif os.environ[name].lower() in ["false", "no", "0"]:
        return False
    else:
        return default


def ENV_STR(name, default=None):
    """
    Returns env variable. If it's not set, returns the default.
    """
    return os.environ.get(name, default)


def ENV_INT(name, default=None):
    """
    Parses env variable as an integer and returns it.
    
    If not set or can't be parsed, returns the default value,
    or None if default isn't given.
    """
    try:
        return int(os.environ.get(name, default))
    except ValueError:
        return default


def ENV_DEC(name, default=None):
    """
    Parses env variable as a Decimal and returns it.
    
    If not set or can't be parsed, returns the default value,
    or None if default isn't given.
    """
    from decimal import Decimal

    try:
        return Decimal(os.environ.get(name, default))
    except ValueError:
        return default


def ENV_LIST(name, separator, default=None):
    """
    Parses env variable as list of strings split by a separator.
    
    Returns the parsed list, or the default if it wasn't defined.
    """
    if default is None:
        default = []

    if name not in os.environ:
        return default
    return os.environ[name].split(separator)