xexe

xexe is Superhog's tool to ingest currency rates from xe.com into our DWH. xexe is a Python CLI application, and this is the repository where it lives.

How to use the tool

Note: the app has only been used so far in a Linux environment. Windows support is dubious.

Install

• Ensure you have Python 3.10> and poetry installed.
• Run poetry install to install dependencies.
• Activate the project's virtual environment. You can use poetry shell.
• Test that everything is working by running xexe smoke-test. You should see a happy pig.

Set up credentials

To use xexe, you will need to have credentials for the xe.com API. Specifically, you need an account id and it's matching api key.

To set up your environment, you should create a .env file and place it in ~/.xexe/.env. You will have to run xexe as the right user to ensure the .env file is found. You can use the .env-example file as a reference. We also recommend running chmod 400 or chmod 600 on it for safety.

Once you have done this, you can run xexe xe-healthcheck. If the connection to the API was successful, you will see some output telling you so.

Using

Remember to activate the project virtual environment.

You can use xexe to get rates and store them locally like this:

xexe get-rates --start-date "2024-01-01" --end-date "2024-01-10" --output my_rates.csv

You can also run without specifying dates. Not specifying end-date will get rates up to today. Not specifying start-date will get dates up to last week.

xexe get-rates --output my_rates.csv

xexe comes with a set of default currencies, but you can also specify the currencies you want to get data for by passing them like this:

# Currencies must be valid ISO 4217 codes and be comma-separated
xexe get-rates --currencies USD,EUR,GBP --output my_rates.csv

The output file will follow this schema:

• date
• from_currency
• to_currency
• exchange_rate
• exported_at

A few more details:

• Running get-rates with an end-date beyond the current date will ignore the future dates. The run will behave as if you had specified today as the end-date.
• Trying to place an end-date before a start-date will cause an exception.
• Running with the option --dry-run will run against a mock of the xe.com API. Format will be valid, but all rates will be 42. This is for testing purposes.

Testing

#TODO Explain how to run tests