turner-townsend-backend-assessment/roman/README.md

Roman numerals converter

Original assessment brief: https://github.com/turner-townsend/backend-assessment/blob/master/README.md#roman-numerals

A simple Python program that converts Roman numerals to Arabic numbers using additive logic.

Supported numerals

Numeral	Value
I	1
V	5
X	10
C	100
M	1000

Usage

python roman.py

Examples

Please enter some Roman numerals: I
I = 1

Please enter some Roman numerals: VI
VI = 5 + 1 = 6

Please enter some Roman numerals: MXVII
MXVII = 1000 + 10 + 5 + 1 + 1 = 1017

Please enter some Roman numerals: ABC
ERROR: Invalid input

Features

• Additive conversion: Treats all numerals as additive (IV = 1 + 5 = 6)
• Case insensitive: Accepts both uppercase and lowercase
• Input filtering: Ignores invalid characters, extracts valid numerals
• Interactive: Continuous input until Ctrl+C

Requirements

• Python 3.10+ (uses pattern matching syntax)
• pytest (for running tests)

Tests

pytest -v

Example output:

➜  roman git:(main) ✗ pytest -v
================================================================ test session starts ================================================================
platform linux -- Python 3.12.2, pytest-8.3.4, pluggy-1.5.0 -- /home/jamey/.venv/bin/python
cachedir: .pytest_cache
rootdir: /home/jamey/Projects/turner-townsend-backend-assessment/roman
plugins: mock-3.14.0, asyncio-0.21.2
asyncio: mode=Mode.STRICT
collected 9 items

test_roman.py::test_valid_single_numerals PASSED                                                                                              [ 11%]
test_roman.py::test_valid_multiple_numerals PASSED                                                                                            [ 22%]
test_roman.py::test_lowercase_input PASSED                                                                                                    [ 33%]
test_roman.py::test_mixed_case_input PASSED                                                                                                   [ 44%]
test_roman.py::test_invalid_characters PASSED                                                                                                 [ 55%]
test_roman.py::test_mixed_valid_and_invalid_characters PASSED                                                                                 [ 66%]
test_roman.py::test_empty_string PASSED                                                                                                       [ 77%]
test_roman.py::test_only_spaces PASSED                                                                                                        [ 88%]
test_roman.py::test_spaces_and_valid_numerals PASSED                                                                                          [100%]

================================================================= 9 passed in 0.02s =================================================================

Design notes

• Simple approach: Uses additive logic only, as the brief states complex Roman numeral rules are not required
• User-friendly: Filters out invalid characters rather than rejecting entire input
• Modern Python: Uses pattern matching (requires Python 3.10+)