Prompt engineering, learned the honest way: by failing at it
A developer's hands-on notebook on coaxing Stable Diffusion, ChatGPT, and Copilot into doing what you actually meant.

What it does
This is a long-form, personal exploration of prompt engineering by phodal, written in early 2023 as the AIGC wave hit. It walks through three creative domains — text-to-image with Stable Diffusion, article writing with ChatGPT, and code generation with GitHub Copilot — showing how prompts evolve from vague descriptions into precise, structured inputs. The repo is mostly a Jupyter-notebook-backed essay, plus a companion tool (click-prompt) that packages the patterns it describes.
The interesting bit
The author’s framing is refreshingly blunt: AI is like Captain America — strong against strong opponents, weak against weak ones — and the prompt is the whole game. The image-generation section is essentially a documented failure log: verbose ChatGPT-embellished descriptions get stripped down to keyword-style prompts, then rebuilt with negative prompts, ControlNet for pose control, and DreamBooth for personal style. There’s also a speculative essay arguing “prompt programming” is the real no-code — code as a disposable byproduct of natural language.
Key highlights
- Covers the full Stable Diffusion prompt pipeline: negative prompts, ControlNet, DreamBooth, and inpainting for hand repair
- Includes a DDD + ChatGPT + Copilot worked example for code generation
- Companion notebooks for translation and code generation exercises
- Frames a personal AI strategy: strengthen architecture skills, build domain-specific small models, keep experimenting
- Honest about the author’s own limits — explicitly not a deep learning expert, writing to update his own mental model
Caveats
- Written in Chinese, and dated February 2023 — the tooling landscape it describes has moved considerably
- The author warns some image sections contain age-restricted content
- It’s an essay with notebooks, not a library — expect reading, not installing
Verdict
Worth a look if you want a practitioner’s field notes from the early prompt-engineering era, especially the image-generation workflow. Skip it if you’re after current, production-grade prompting techniques — this is a historical document, and a charmingly candid one.
Frequently asked
- What is phodal/understand-prompt?
- A developer's hands-on notebook on coaxing Stable Diffusion, ChatGPT, and Copilot into doing what you actually meant.
- Is understand-prompt open source?
- Yes — phodal/understand-prompt is an open-source project tracked on heatdrop.
- What language is understand-prompt written in?
- phodal/understand-prompt is primarily written in Jupyter Notebook.
- How popular is understand-prompt?
- phodal/understand-prompt has 5.6k stars on GitHub and is currently holding steady.
- Where can I find understand-prompt?
- phodal/understand-prompt is on GitHub at https://github.com/phodal/understand-prompt.