How Python was Shaped by leaky Internals, Armin Ronacher, Flask framework
What it is
Armin Ronacher, creator of Flask, explains how CPython's internals and C API leak into the language's semantics. Using examples like the complexity of the add operation, he shows why Python is hard to optimize or reimplement.
Why Hacker News recommends it
It is HN's standard answer to why Python cannot easily get much faster, and is recommended by people who work on JITs and alternative runtimes.
- 15 people recommended it
- 16 different months
- 7 strong recommendations
- first 2017, last 2025
What HN commenters said
“This talk shows how bad of shape it's really in.”
Shows CPython internals lack a spec and hinder new runtimes.
ericfrederich, 2017-01 · Strong recommendation · in “Grumpy: Go running Python”
“Here's a great talk from the author of the famous Flask library in Python”
Great talk on fundamental problems in Python semantics.
eigenspace, 2020-02 · Strong recommendation · in “JuliaLang: The Ingredients for a Composable Programming Language”
“I highly recommend this talk by Armin Ronacher”
Accompaniment to article on Python's leaky internals.
nerdponx, 2020-09 · Strong recommendation · in “Python's Innards: Introduction (2010)”
“I highly recommend the two videos posted here”
Details limits of Python optimization.
arc776, 2020-10 · Strong recommendation · in “Attempts to make Python fast”
“This excellent talk describes how the semantics of the "add" operation are much more complex than generally described.”
Shows how complex Python's add operation semantics really are.
haberman, 2021-09 · Strong recommendation · in “Writing Python Extensions in Assembly”
“I thought this presentation by Armin Ronacher (the creator of Flask and Jinja) was very enlightening”
Enlightening presentation on Python's leaky internals.
fault1, 2022-01 · Strong recommendation · in “Faster CPython (2021) [pdf]”
“It explains why CPython can't improve on many things.”
Explains why CPython can't improve on many things.
the_duke, 2017-01 · Recommendation · in “Grumpy: Go running Python”
“I'll just refer you to this talk”
Covers a long list of Python implementation problems.
dom0, 2017-06 · Recommendation · in “RTL MJIT – Register transfer language VM and JIT for Ruby”
Excerpts from Hacker News comments, linked to the originals. Summaries and labels were written by a language model from those comments.
Topics: cpython, performance, jit, c api, language semantics, armin ronacher
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