The Megahertz

Episode 24 of the core.py podcast, hosted by Pablo Galindo and Łukasz Langa, titled "The Megahertz" was published on July 12, 2025 and runs 102 minutes.

July 12, 2025 ·102m · core.py

Summary

Python 3.14? That's old news. Let's talk about the first big feature of Python 3.15 -- a built-in sampling profiler for Linux, macOS, and Windows. We also cover improvements in perf support, discuss memory.python.org, and as usual, recent changes in the codebase.## Timestamps(00:00:00) INTRO(00:02:43) PART 1: THE SAMPLING PROFILER(00:05:07) Built-in profile is bad, long live cProfile(00:10:54) Out-of-process profiling(00:12:18) Shortcuts Compromise Accuracy, Leading Eventually to Numerous Errors(00:16:07) Selfish Łukasz vs benevolent Pablo(00:23:11) How does a sampling profiler even work?(00:30:42) One meeellion huuurtzzz(00:32:40) Free threading makes it extra spicy(00:41:26) AsyncIO makes it even spicier(00:49:49) You made this? I made this(00:54:06) What if the profiled process changes during sampling?(00:57:33) Coming in October 2026(01:04:30) PART 2: PR OF THE WEEEEEEK(01:14:14) memory.python.org launched(01:23:15) PART 3: WHAT'S GOING ON IN CPYTHON(01:26:45) Performance updates(01:30:24) Features & Curiosities(01:41:45) OUTRO

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