# 失敗的測試 (pytest)
def test_parse_price_handles_commas:
 assert parse_price("1,234.50") == 1234.50
# 目前的實作
def parse_price(s: str) -> float:
 return float(s)

import re
def parse_price(s: str) -> float:
 # Strip non‑numeric except dot and minus
 cleaned = re.sub(r"[^0-9.\-]", "", s)
 # Normalize commas used as thousands separators
 cleaned = cleaned.replace
 # Guard empty or multiple dots
 if cleaned.count > 1 or not cleaned.strip:
 raise ValueError(f"Invalid price: {s}")
 return float(cleaned)

def test_parse_price_rejects_invalid:
 import pytest
 with pytest.raises(ValueError):
 parse_price("--12.3.4")