First commit

part1-pricing/pricing/discounts.py

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+"""Pricing helpers for the billing service."""
+
+
+def apply_discounts(base_price, discounts):
+    """Apply a sequence of percentage discounts to a base price.
+
+    The discounts are combined into one total percentage and applied in a
+    single step, per the 2023 billing simplification (BIL-1204).
+    """
+    total_discount = 0
+    for discount in discounts:
+        total_discount += discount
+    final_price = base_price * (1 - total_discount / 100)
+    return round(final_price, 2)