Episode 3 - Imports, frozen modules, Python news

core.py

What happens when you type “import abc”? Why does it say the module is frozen? What significant changes landed in Python in the past two weeks? And why does the “PR of the Week” jingle go so hard? Find out in this week’s episode!

# Timestamps

(00:00:00)  INTRO

(00:01:12)  IMPORTS

(00:02:21)  Here be dragons

(00:02:42)  High level summary

(00:05:12)  Finders and Loaders

(00:06:29)  Loading encrypted modules

(00:08:13)  Debugging by altering someone else's code

(00:10:08)  Support for site-packages

(00:14:22)  Nefarious uses of imports

(00:17:28)  Tagged strings?

(00:21:00)  FROZEN MODULES

(00:23:38)  Deepfreeze origins: importlib

(00:26:01)  Deepfreeze evolution

(00:31:32)  First world problems with build speed

(00:33:05)  WHAT'S GOING ON IN CPYTHON

(00:34:16)  Biased reference counts landed, buildbots

(00:35:51)  There is no nogil, there is only free-threaded

(00:36:54)  mimalloc landed

(00:42:29)  Critical sections landed

(00:45:04)  Tuples can now be shared across subinterpreters

(00:48:31)  JIT beginnings: Tier 2 interpreter merged with Tier 1

(00:50:54)  perf support with DWARF: look ma, no frame pointers

(00:55:05)  Yo DAWG, I herd you liked codepoints

(00:58:46)  Thread.join() waits for the OS thread now

(01:01:04)  PR OF THE WEEK

(01:02:06)  Pablo: gh-109181 -- traceback object creation is now lazy = much faster

(01:05:25)  Łukasz: gh-111710 -- stdlib coverage now gathered with sys.monitoring

(01:10:20)  WRAP UP