Making a Python interpreter in 1024 bytes
- ID
- 22061
- Status
- summarized
- Published
- 07 Sep 2026, 7:14 AM
- Fetched
- 09 Sep 2026, 2:49 AM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://austinhenley.com/blog/python1024.html
- Source URL
- https://hnrss.org/best
Summary
- Score
- 4.5
- Created
- 09 Sep 2026, 2:52 AM
- Tags
- Audience
- developersvibe_coders
What happened
Austin Z. Henley challenged himself to write a Python interpreter in 1024 bytes of C, with no macros or library tricks. He found 512 bytes insufficient for even a basic calculator, so he expanded to 1024 and focused on supporting a subset of Python syntax that 'looks Pythony'—def, colons, indentation, if/else, for loops, and FizzBuzz—using a recursive descent parser with global state, a fixed 999-char source buffer, and zero error handling.
Why it matters
This is a code-golf thought experiment, not a production tool—nobody should switch interpreters because of it. The practical value is pedagogical: it strips a language interpreter down to its bare mechanics (tokenization, recursive descent parsing, a symbol table as a 256-int array, immediate execution during parsing), which is useful if you want to understand how languages work under the hood or are considering building a small DSL.
Discussion angle
What's the minimum subset of a language that still 'feels' like that language to users—and how does that question apply if you're designing a small DSL or agent scripting language for your own product?