Energy usage calculations

Application calculates bill based on tariff and received JSON data payload, containing electricity usage - stored in data folder: readings.json.

Assumptions provided in the instructions

You can assume:

• All times are UTC.
• We're only dealing with £ denominated billing.
• You only need to handle electricity and gas billing.
• Energy is consumed linearly.
• The billing date is the last day of the month.
• Readings are always taken at midnight.
• There is only one meter reading per billing period.
• The JSON file structure will remain the same in any follow on exercise.

Setup

Python3.8 installation instructions: https://docs.python.org/3/using/index.html

Ensure Python3.8 is available on the system and that you are in the directory of the project, where Pipfile is.

sudo pip install pipenv
pipenv install

For development use:

pipenv install --dev

Running

Default

pipenv run python main.py

Application is able to accept arguments:

--member_id
--account_id
--bill_date
--energy_source

E.g.:

 pipenv run python main.py \
 --member_id member-123 \
 --account_id account-abc \
 --bill_date 2020-08-21 \
 --energy_source electricity

Testing

pipenv run pytest

Examples of running specific tests:

pipenv run pytest tests/test_bill_member.py
pipenv run pytest tests/test_bill_member.py::TestBillMember::test_calculate_bill

CircleCI

Project is able to use Continuous Integration via CircleCI. Please check configuration in .circleci/config.yml.

Included in the implementation:

1. A small program which, given a set of meter readings, computes a member’s monthly energy bill.
2. Tests.