--- title: Tiny Great Languages: BASIC | daily.dev description: A walkthrough of building a minimal BASIC interpreter in Python, covering the classic numbered-line editing model, a hash-map based program store, a recursive... canonical: https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Tiny Great Languages: BASIC | daily.dev og:description: A walkthrough of building a minimal BASIC interpreter in Python, covering the classic numbered-line editing model, a hash-map based program store, a recursive... og:url: https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk og:image: https://api.daily.dev/og/posts/ejbJJIRbK.png og:image:alt: Tiny Great Languages: BASIC og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Tiny Great Languages: BASIC **[zserge's blog](https://daily.dev/sources/zserge)** · 7 min read · 0 upvotes · 0 comments ## Summary A walkthrough of building a minimal BASIC interpreter in Python, covering the classic numbered-line editing model, a hash-map based program store, a recursive descent expression parser, and a compact statement dispatcher. The full interpreter fits in 53 lines and supports PRINT, INPUT, GOTO, IF, and editing commands like NEW, LIST, and BYE. The piece demonstrates the interpreter running a factorial program and suggests extensions like FOR/NEXT loops, GOSUB/RETURN, strings, and arrays. It's part of a series exploring small, historically significant programming languages, following an earlier post on Assembly. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How can I write a simple BASIC interpreter in Python? A minimal BASIC interpreter can be built in about 53 lines of Python by storing numbered lines in a dictionary, using a recursive descent parser (expr/term/factor functions) for arithmetic, and a stmt() function that dispatches commands like PRINT, INPUT, GOTO, and IF through a lambda-based dictionary of operations, using a variable named '#' to track the current line number for jumps. _daily.dev surfaces build-it-yourself interpreter writeups for developers exploring language design._ ### How do you implement GOTO and line jumping in a tiny interpreter without a full instruction pointer system? Line jumping can be implemented by storing a special variable, often named '#', that holds the current line number, then having GOTO update that variable via an expression evaluation and having the statement loop fetch the next code line whose number is greater than or equal to the current value using a sorted dictionary lookup. _daily.dev helps developers researching interpreter and parser design patterns like this one._ ## Similar posts on daily.dev - [Completing a BASIC language interpreter in 2025](https://daily.dev/posts/completing-a-basic-language-interpreter-in-2025-okykqn1ka) · Hacker News · 0 upvotes · 0 comments - [A 1024 Byte Python Interpreter](https://daily.dev/posts/a-1024-byte-python-interpreter-ombsbouew) · Hackaday · 0 upvotes · 0 comments - [Making a Python interpreter in 1024 bytes](https://daily.dev/posts/making-a-python-interpreter-in-1024-bytes-vi1kzt7ex) · Lobsters · 0 upvotes · 0 comments - [Acidica](https://daily.dev/posts/acidica-9mjbibp7h) · Planet Python · 0 upvotes · 0 comments - [T3X.ORG nmhbasic](https://daily.dev/posts/t3x-org-nmhbasic-k7oor3t8d) · Two Stop Bits · 0 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#retrocomputing](https://daily.dev/tags/retrocomputing) [View this post on daily.dev](https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Tiny Great Languages: BASIC","url":"https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk"},"datePublished":"2026-08-23T10:20:14.902Z","dateModified":"2026-08-23T10:22:02.891Z","description":"A walkthrough of building a minimal BASIC interpreter in Python, covering the classic numbered-line editing model, a hash-map based program store, a recursive...","image":"https://media.daily.dev/image/upload/s--HRgLpUt6--/f_auto/v1722860399/public/Placeholder%2003","thumbnailUrl":"https://media.daily.dev/image/upload/s--HRgLpUt6--/f_auto/v1722860399/public/Placeholder%2003","isAccessibleForFree":true,"articleSection":"zserge's blog","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"zserge's blog","logo":"https://media.daily.dev/image/upload/s--KQnFBOIT--/f_auto,q_auto/v1787480407/logos/zserge","url":"https://daily.dev/sources/zserge"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"python,retrocomputing","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"zserge's blog","item":"https://daily.dev/sources/zserge"},{"@type":"ListItem","position":3,"name":"Tiny Great Languages: BASIC"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/tiny-great-languages-basic-ejbjjirbk#faq","mainEntity":[{"@type":"Question","name":"How can I write a simple BASIC interpreter in Python?","acceptedAnswer":{"@type":"Answer","text":"A minimal BASIC interpreter can be built in about 53 lines of Python by storing numbered lines in a dictionary, using a recursive descent parser (expr/term/factor functions) for arithmetic, and a stmt() function that dispatches commands like PRINT, INPUT, GOTO, and IF through a lambda-based dictionary of operations, using a variable named '#' to track the current line number for jumps. daily.dev surfaces build-it-yourself interpreter writeups for developers exploring language design."}},{"@type":"Question","name":"How do you implement GOTO and line jumping in a tiny interpreter without a full instruction pointer system?","acceptedAnswer":{"@type":"Answer","text":"Line jumping can be implemented by storing a special variable, often named '#', that holds the current line number, then having GOTO update that variable via an expression evaluation and having the statement loop fetch the next code line whose number is greater than or equal to the current value using a sorted dictionary lookup. daily.dev helps developers researching interpreter and parser design patterns like this one."}}]} ```