# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Overview

This is a single-file Python CLI (`cpc_price.py`) that scrapes Taiwan CPC's (中油) historical fuel price page and outputs the data in various formats.

## Running the Script

```bash
python3 cpc_price.py                  # table output (default)
python3 cpc_price.py --ad             # convert ROC dates to AD
python3 cpc_price.py --latest         # show only the most recent record
python3 cpc_price.py -f csv           # CSV output
python3 cpc_price.py -f json --ad     # JSON output with AD dates
```

## Dependencies

```bash
pip install requests beautifulsoup4
```

## Key Notes

- **SSL**: The CPC website has a certificate missing a Subject Key Identifier, so `verify=False` is used with `urllib3` warnings suppressed.
- **Date format**: The site uses ROC (Republic of China) calendar dates (e.g. `115/03/16`). The `--ad` flag converts them by adding 1911 to the year.
- **Data source**: `https://www.cpc.com.tw/historyprice.aspx?n=2890` — shows roughly the last 7 weekly price adjustments.
- **Parsing**: The page has a single `<table>` with headers in the first `<tr>`. If the site restructures its HTML, the `fetch_prices()` function is the place to fix parsing.