script_5.py - List Sorting and Custom Sort Keys

Code

See script_5.py for full code.

Explanation

Line 9-15: List of dictionaries - Each dict represents a product - Dict keys: "name", "price", "rating", "stock" - products is list type containing dict elements

Line 21: by_price = sorted(products, key=lambda x: x["price"]) - sorted() is built-in function returning new sorted list - Original list unchanged (non-mutating) - key parameter specifies sort criteria - lambda x: x["price"] is anonymous function - Lambda takes dict x, returns price value - Sorts by price in ascending order (default)

Line 27: by_rating = sorted(products, key=lambda x: x["rating"], reverse=True) - reverse=True parameter sorts descending (high to low) - Boolean parameter changes sort order

Line 33: by_availability = sorted(products, key=lambda x: (x["stock"] == 0, -x["rating"])) - Lambda returns tuple for multi-level sorting - First sorts by x["stock"] == 0 (boolean: False < True) - Then sorts by -x["rating"] (negative for descending within group) - Out-of-stock items come last, within each group sorted by rating

Line 41: case_insensitive = sorted(words, key=str.lower) - str.lower is method reference (no parentheses) - Applied to each string element - Returns lowercase version for comparison - Original strings unchanged