envpy 0.0.4

Python library for loading config from environment variables.

envpy
=====

Overview
--------
Python library for loading config from environment variables.
Suitable for implementing the config requirements of a 12-factor app:
https://12factor.net/config

Getting Started
---------------

Installation
````````````
To install use pip:
.. code-block:: guess
$> pip install envpy

Requirements before installation:
- python3
- pip3

Usage
`````
.. code-block:: python
"""Basic usage script for envpy"""

import envpy

CONFIG = envpy.get_config({
# This will raise an error if it cannot be found in the environment
# because no default has been set.
'SECRET_KEY': envpy.Schema(value_type=str),
# This has a default value and as such won't raise an error if it cannot
# be found in the environment. However, the value type is set to 'int'
# which means that an error will be raised if a value is present in the
# environment but cannot be parsed as an integer.
'NUM_WORKERS': envpy.Schema(value_type=int, default=4),
})

if __name__ == '__main__':
print('Secret Key:', config['SECRET_KEY'])
print('Number of workers:', config['NUM_WORKERS'])

Value Types
-----------

**str**

No parsing is applied and the string is returned directly from the environment.

**int**

The value will be parsed as an integer. Must match: ^[0-9]+$.

**float**

The value will be parsed as a float. Must match: ^[0-9]+\.[0-9]+$.

**bool**

The value will be parsed as a boolean. Must be one of the following:
- "1" (True)
- "0" (False)
- "true" (True, case insensitive)
- "false" (False, case insensitive)


Development
-----------

Installation
````````````
This project makes use of virtual environments to provision your development environment. Once the following requirements have been met further installation is managed automatically by the Makefile.

Requirements before provisioning:
- python3
- pip3
- virtualenv
- make

Usage
`````
The following commands will create a virtual environment (if not already present) for the application and will install the necessary dependencies there before running the requested command.

Run the package:
.. code-block:: guess
$> make

Run the unit tests:
.. code-block:: guess
$> make test

Run the linter:
.. code-block:: guess
$> make lint

Rebuild your virtual environment:
.. code-block:: guess
$> make rebuild_venv