enve 0.1.0

An environment variable parser library with type hint and conversion support.

enve

An environment variable parser library with type hint and conversion support.

The complete documentation is available here.

Usage

enve.get is the main package function. It's essentially os.getenv on (arguably unnecessarily strong) steroids. It's advantage is that it will automatically validate the environment variable's data type based on what you desire and provide typing support for the used variable. For complete details, see the enve.get function docstring.

The example below illustrates how you can obtain environment variables and convert them to a desired data type.

import enve


ENVVAR = enve.get("ENVVAR")  # will be parsed and typed as `str`
ENVVAR_STR = enve.get("ENVVAR", dtype=str)  # will be parsed and typed as `str`
MY_SWITCH = enve.get("MY_SWITCH", dtype=bool)  # will be parsed and typed as `bool`
HASH_SALT = enve.get("HASH_SALT", dtype=bytes)  # will be parsed and typed as `bytes`
RANDOM_SEED = enve.get("RANDOM_SEED", dtype=int)  # will be parsed and typed as `int`
MY_PI = enve.get("MY_PI", dtype=float)  # will be parsed and typed as `float`
CUDA_VISIBLE_DEVICES = enve.get("CUDA_VISIBLE_DEVICES", dtype=list)  # will be parsed and typed as `list`

Supported data types are bool, bytes, float, int, str (the default), and list.

In all these examples, a ValueError will be raised if the environment variable is not defined. To use a default value, set the default parameter accordingly. Note that the default value's type must be None or the same as the expected return type.

import enve


ENVVAR_WITH_DEFAULT = enve.get("MISSING_ENVVAR", default="foobar")

enve.get also supports Docker secrets. By setting the docker_secret parameter to True or to the name of a Docker secret, enve.get will attempt to retrieve its value (even if unset in the current environment).

import enve


# The following snippet will:
# 1. Check whether the `MY_SECRET` envvar exists. If true, this will be returned.
# 2. Check whether `/run/secrets/MY_SECRET` exists. If true, the file will be read
#    and the value will be returned.
# 3. Check whether `/run/secrets/my_secret` exists. If true, the file will be read
#    and the value will be returned.
# 4. Raise a `ValueError` as no default is provided.
MY_SECRET = enve.get("MY_SECRET", docker_secret=True)