subscriptions-to-csv 2.0.0

Convert subscription lists to CSV with EUR conversion

Subscriptions to CSV

A Python package built as a Nix flake utility that provides both CLI and library functionality to convert subscription lists into CSV files with EUR conversions and totals. Includes comprehensive type hints, error handling, and a full test suite.

Description

This tool processes subscription data (from files or strings) containing service names and prices, generates CSV output with columns for Service, Price, Currency, and Price in EUR (with automatic USD to EUR conversion), and calculates total sums in EUR.

Available as both:

• Command-line tool: Process files directly from the terminal
• Python library: Import and use programmatically in your applications

The project includes comprehensive unit tests covering all major functionality and supports PyPI distribution.

Installation

Option 1: PyPI (Library + CLI)

pip install subscriptions-to-csv

This installs both the command-line tool and Python library.

Option 2: Nix Flake (Development/Direct Usage)

Ensure you have Nix installed with flakes enabled.

Clone the Repository

git clone https://github.com/MBanucu/subscriptions-to-csv.git
cd subscriptions-to-csv

# Allow direnv to load the .envrc file (one-time setup)
direnv allow

The project uses direnv for automatic development environment loading. After running direnv allow, the Nix devShell will be automatically activated whenever you enter the directory.

Direct from GitHub

You can also use this flake directly from GitHub without cloning:

# Run with default files
nix run github:MBanucu/subscriptions-to-csv#subscriptions-to-csv

# Specify input and output files
nix run github:MBanucu/subscriptions-to-csv#subscriptions-to-csv path/to/input.txt path/to/output.csv

# Show help
nix run github:MBanucu/subscriptions-to-csv#subscriptions-to-csv -- --help

This approach allows you to use the tool immediately without downloading the source code.

Note: When using nix run directly from GitHub, use positional arguments for input/output files or the -- separator before option flags. Both approaches work the same way. Options work normally when running locally after cloning.

Usage

CLI Usage

Basic Usage

# Enter the development shell (or use direnv for automatic loading)
nix develop

# Run the converter
subscriptions-to-csv

This will read subscriptions.txt and output subscriptions.csv.

Note: If you have direnv installed, the development shell will be automatically activated when you enter the directory, making the nix develop step unnecessary.

Custom Files

# Specify input and output files (positional)
nix run .#subscriptions-to-csv path/to/input.txt path/to/output.csv

# Or using options
nix run .#subscriptions-to-csv --input path/to/input.txt --output path/to/output.csv

Direct Run

nix run .#subscriptions-to-csv

Help

# Show usage information
nix run .#subscriptions-to-csv -- --help

Note: The -- separates nix arguments from application arguments.

Library Usage

When installed via pip, you can use the package as a Python library:

Basic Usage

from subscriptions_to_csv import convert_subscriptions

# Convert from string data
data = """Netflix
$15.99 USD
Spotify
€9.99"""

subscriptions, total = convert_subscriptions(data)
print(f"Total: €{total:.2f}")
for sub in subscriptions:
    print(f"{sub['Service']}: {sub['Price']} {sub['Currency']} = €{sub['PriceEUR']}")

Advanced Usage

from subscriptions_to_csv import SubscriptionConverter, fetch_exchange_rate

# Manual control over exchange rates
converter = SubscriptionConverter()
converter.set_exchange_rate(0.85)  # Set custom rate

# Convert and get data
subscriptions = converter.convert("Netflix\n$15.99 USD")
total, count = converter.convert_with_total("Netflix\n$15.99 USD")

# Write to CSV file
converter.convert_to_csv("Netflix\n$15.99 USD", "output.csv")

# Individual functions
rate = fetch_exchange_rate()

Input Format

The input file should contain subscription data in the following format:

Service Name
	Price Currency
Service Name
	Price Currency

Example:

Spotify
	12.99 €
Netflix
	19.99 €
GutHub Copilot Pro
	$10.00 USD

Supported currencies: € (Euro), USD (automatically converted to EUR).

Output

The output CSV contains:

• Service: The subscription name
• Price: The original price
• Currency: The original currency
• PriceEUR: The price in EUR (converted if necessary)

Plus a total sum in EUR printed to the console.

Example output:

Service,Price,Currency,PriceEUR
Spotify,12.99,€,12.99
Netflix,19.99,€,19.99
GutHub Copilot Pro,10.00,USD,8.62
Total in EUR: 41.60

Configuration

• Input file: Default subscriptions.txt, can be overridden with --input or positional argument
• Output file: Default subscriptions.csv, can be overridden with --output or positional argument
• Exchange rate: Automatically fetched from exchangerate-api.com
• Fallback: If API fails, uses rate 1.0

Test Coverage

The project includes comprehensive unit tests covering:

• Command-line argument parsing (default, positional, optional)
• Exchange rate API fetching with fallback behavior
• Subscription data parsing and currency conversion
• CSV file generation and total calculations
• Integration testing of the full workflow

Requirements

CLI Usage

• Nix with flakes support (for nix-based installation)
• Internet connection for exchange rate fetching

Library Usage

• Python 3.6+ (3.13 recommended)
• pip for installation
• Internet connection for exchange rate fetching

Development

Project Structure

The project is structured as a proper Python package:

• flake.nix: Nix flake configuration for multi-platform builds
• flake.lock: Nix flake lock file
• .envrc: Direnv configuration for automatic devShell loading
• pyproject.toml: Python package configuration and build system
• subscriptions_to_csv/: Main Python package
  • __init__.py: Package initialization and exports
  • converter.py: Core conversion functions and classes
  • cli.py: Command-line interface
• tests/test_main.py: Comprehensive unit test suite

Building

Build the Python package:

nix build

This creates a proper Python package using buildPythonPackage that can be installed and distributed.

Testing

Run the comprehensive test suite including CLI integration tests:

# Run unit tests (direnv automatically loads environment)
pytest

# Or manually enter devShell and run tests
nix develop --command pytest

# Run flake checks (includes CLI functionality tests)
nix flake check

# Run specific flake checks
nix build .#checks.x86_64-linux.help-test
nix build .#checks.x86_64-linux.basic-test
nix build .#checks.x86_64-linux.named-args-test

The flake checks verify that:

• The --help command works correctly
• Basic functionality with sample data works
• Positional and named arguments function properly

Testing

# Run the test suite (environment loads automatically with direnv)
pytest

# Or enter devShell manually
nix develop
pytest

# Run specific tests
pytest tests/test_main.py
pytest -k "parse"  # Run tests matching pattern

# Manual testing - Run with defaults
nix run .#subscriptions-to-csv

# Test CLI options
nix run .#subscriptions-to-csv -- --help

# Check the output CSV and total

Release Process

The project uses automated semantic versioning with cutting-edge tooling. When you push commits to the main branch:

1. Conventional commits trigger automatic version analysis
2. Semantic-release v25.0.2 determines version bumps and generates changelogs
3. GitHub Actions v6.0.0 handles the complete release pipeline
4. Version files are automatically updated and committed
5. PyPI publishing via trusted publisher authentication

Example workflow:

# Make changes
git add .
git commit -m "feat: add new export format"

# Push to main - triggers automated release (13-16 seconds)
git push origin main

Tools Used:

• semantic-release: v25.0.2 (latest stable)
• GitHub Action: cycjimmy/semantic-release-action v6.0.0
• Node.js: 24+ compatible
• Plugins: changelog, git (optimized for Python projects)

Code Style

See AGENTS.md for detailed coding guidelines.

Releases

This project uses automated semantic versioning and publishing with semantic-release v25.0.2 and cycjimmy/semantic-release-action v6.0.0:

🎉 Fully automated release system now active!

Automated Releases

• Trigger: Push to main branch with conventional commits
• Versioning: Automatic based on commit types (feat:, fix:, etc.)
• Publishing: Automatic PyPI publishing via trusted publisher
• Changelog: Automatically generated from commit messages
• Performance: 13-16 second release cycles
• Compatibility: Latest Node.js 24 and plugin ecosystem support

Commit Types & Releases

Commit Type	Release Type	Version Bump	Example
fix:	Patch	0.0.1	fix: handle empty files
feat:	Minor	0.1.0	feat: add export formats
feat!: or BREAKING CHANGE:	Major	1.0.0	feat!: redesign API
docs:, refactor:, test:, chore:	No release	-	docs: update README

Manual Releases

For special cases, create releases manually:

gh release create v1.2.3 --generate-notes

Contributing

1. Fork the repository
2. Create a feature branch
3. Make changes
4. Run tests: pytest (direnv automatically loads the environment)
5. Test CLI: nix run .#subscriptions-to-csv -- --help
6. Test library: python3 -c "from subscriptions_to_csv import convert_subscriptions; print('Library works')"
7. Submit a pull request

License

This project is open source. Please check the license file if present.