--- title: Debug Python Like a Pro in VS Code | daily.dev description: A walkthrough of debugging a Python FastAPI application using VS Code's built-in debugger. Covers setting up a launch.json configuration for Uvicorn, placing... canonical: https://daily.dev/posts/debug-python-like-a-pro-in-vs-code-oxvnbmvdr twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Debug Python Like a Pro in VS Code | daily.dev og:description: A walkthrough of debugging a Python FastAPI application using VS Code's built-in debugger. Covers setting up a launch.json configuration for Uvicorn, placing... og:url: https://daily.dev/posts/debug-python-like-a-pro-in-vs-code-oxvnbmvdr og:image: https://api.daily.dev/og/posts/oxVNbMvDR.png og:image:alt: Debug Python Like a Pro in VS Code 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. # Debug Python Like a Pro in VS Code **[Visual Studio Code](https://daily.dev/sources/vscode)** · 12 min read · 0 upvotes · 0 comments ## Summary A walkthrough of debugging a Python FastAPI application using VS Code's built-in debugger. Covers setting up a launch.json configuration for Uvicorn, placing breakpoints, using the Variables and Watch panels, navigating the call stack, and using step over/step into controls to isolate a bug. The bug turns out to be a Python dictionary unpacking issue where a new local dictionary is created instead of mutating the existing one in-place, and the fix is demonstrated using the dict.update() method. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#python](https://daily.dev/tags/python), [#vscode](https://daily.dev/tags/vscode), [#fastapi](https://daily.dev/tags/fastapi) [View this post on daily.dev](https://daily.dev/posts/debug-python-like-a-pro-in-vs-code-oxvnbmvdr) ```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":"Debug Python Like a Pro in VS Code","url":"https://daily.dev/posts/debug-python-like-a-pro-in-vs-code-oxvnbmvdr","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/debug-python-like-a-pro-in-vs-code-oxvnbmvdr"},"datePublished":"2026-07-30T14:06:55.523Z","dateModified":"2026-07-30T14:12:30.200Z","description":"A walkthrough of debugging a Python FastAPI application using VS Code's built-in debugger. 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