Technical notes by KbWen

Notes on AI, machine learning, Python, and data engineering, plus tools I build.

Latest posts

AI Systems

How FlashAttention computes softmax one block at a time

One query's attention scores, split into two blocks and worked through by hand, to see how FlashAttention gets the softmax without having all the scores at once.

2026-11-06 · 6 min read · 1261 words · KbWen · EN
Python

Python 寫了 __eq__ 之後,物件為什麼不能放進去 set

替 class 寫了 __eq__,正常使用卻會出現 unhashable type 的錯誤。來看看 Python 為什麼這樣處理,以及 __hash__ 該怎麼做。

2026-11-06 · 3 min read · 1457 words · KbWen · ZH
AI Systems

Setting effort on Claude Haiku 5.5

A look at the effort levels on Claude Haiku 5.5, and what to check when picking one.

2026-11-06 · 4 min read · 845 words · KbWen · EN
AI Systems

Claude Haiku 5.5 超過 100,000 tokens 的請求怎麼計價

我們來看看 Claude Haiku 5.5 的價格,以及每次請求的差別

2026-11-06 · 3 min read · 1310 words · KbWen · ZH

Latest by category

More posts

Machine Learning

model.eval() and torch.no_grad() in PyTorch

We look at what model.eval() and torch.no_grad() each change when a model runs at test time.

2026-11-02 · 4 min read · 662 words · KbWen · EN
Python

Python [[0]*3]*3 修改其中一格,為什麼三列都跟著變

用乘號建立二維串列,改了一格卻三列一起變,我們來看看這三列到底是什麼。

2026-11-02 · 3 min read · 1114 words · KbWen · ZH
AI Systems

Passing back reasoning items in the OpenAI Responses API

We look at the reasoning items the OpenAI Responses API returns during a tool loop and how to send them back.

2026-11-02 · 3 min read · 564 words · KbWen · EN
AI Systems

OpenAI 的 reasoning tokens 怎麼計費

我們來看看 OpenAI 的 reasoning tokens 是什麼,以及 API 的回傳用量。

2026-11-02 · 2 min read · 875 words · KbWen · ZH
AI 為什麼愛附和使用者?RLHF 訓練中的阿諛奉承現象
AI Systems

AI 為什麼愛附和使用者?RLHF 訓練中的阿諛奉承現象

我們來看看 Anthropic 的研究怎麼測量出 AI 助理會附和使用者,又是怎麼發現原因出在人類偏好資料和偏好模型上。

2026-10-30 · 4 min read · 1699 words · KbWen · ZH
LLM sycophancy, RLHF and preference models
AI Systems

LLM sycophancy, RLHF and preference models

A look at Anthropic's paper on sycophancy in AI assistants and human preference judgments.

2026-10-30 · 5 min read · 893 words · KbWen · EN