René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Performance gap of match statements of classes compared with equivalent Python 3.9 code","articleBody":"Im doing some micro-benchmarks of the `match` statement.\r\n\r\nThe following comparison shows two functionally equivalent functions of the class matching pattern in the `match` statement.\r\n\r\n```python\r\nclass Driver:\r\n    def __init__(self, name, team, **extra):\r\n        self.name = name\r\n        self.team = team\r\n        self.extra = extra\r\n\r\ndef bench_class_matching_statement():\r\n    drivers = [\r\n        Driver(name=\"Max Verstappen\", team=\"Red Bull\", ),\r\n        Driver(name=\"Sergio Perez\", team=\"Red Bull\", ),\r\n        Driver(name=\"Charles Leclerc\", team=\"Ferrari\", ),\r\n        Driver(name=\"Lewis Hamilton\", team=\"Mercedes\", ),\r\n    ]\r\n\r\n    for _ in range(100_000):\r\n        for driver in drivers:\r\n            match driver:\r\n                case Driver(name=\"Max Verstappen\"): desc = f\"Max Verstappen, the current world #1\"\r\n                case Driver(name=name, team=\"Ferrari\"): desc = f\"{name}, a Ferrari driver!! 🐎\"\r\n                case Driver(name=name, team=team): desc = f\"{name}, a {team} driver.\"\r\n                case _: desc = \"Invalid request\"\r\n            # print(desc)\r\n\r\n\r\ndef bench_class_matching_logical():\r\n    drivers = [\r\n        Driver(name=\"Max Verstappen\", team=\"Red Bull\", ),\r\n        Driver(name=\"Sergio Perez\", team=\"Red Bull\", ),\r\n        Driver(name=\"Charles Leclerc\", team=\"Ferrari\", ),\r\n        Driver(name=\"Lewis Hamilton\", team=\"Mercedes\", ),\r\n    ]\r\n\r\n    for _ in range(100_000):\r\n        for driver in drivers:\r\n            if not isinstance(driver, Driver):\r\n                desc = \"Invalid request\"\r\n            elif driver.name == \"Max Verstappen\":\r\n                desc = f\"Max Verstappen, the current world #1\"\r\n            elif driver.team == \"Ferrari\": \r\n                desc = f\"{driver.name}, a Ferrari driver!! 🐎\"\r\n            else:\r\n                desc = f\"{driver.name}, a {driver.team} driver.\"\r\n            # print(desc)\r\n```\r\n\r\nPython 3.11 executes `bench_class_matching_statement()` at 4x the execution time of `bench_class_matching_logical()`\r\nPython 3.10 executes `bench_class_matching_statement()` at 2.5x the execution time of `bench_class_matching_logical()`\r\n\r\nPython 3.11b1 is showing a speedup of both functions (which is great). \r\n\r\nPattern matching for sequences and mapping is faster than the equivalent Python code, but for classes it is significantly slower.","author":{"url":"https://github.com/tonybaloney","@type":"Person","name":"tonybaloney"},"datePublished":"2022-05-17T04:29:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/92868/cpython/issues/92868"}