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Untangling deeply nested if/else logic is one of the hardest parts of working in real-world Python codebases. In this video, I take a brutally messy example full of indentation, duplicated conditions, and hidden business rules, and systematically break it down into clean, readable logic. You’ll see how to write characterization tests to protect the existing behavior, how to flatten the structure using guard clauses, how to simplify and combine conditions, and how to deal with special cases like admin overrides without breaking anything. By the end, you’ll understand exactly how to transform complicated boolean logic into code that’s easy to read, easy to test, and easy to extend.

🔥 GitHub Repository: https://git.arjan.codes/2025/logic.

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🔖 Chapters:
0:00 Intro
0:48 Why Code Like This Happens
2:57 Write Characterization Tests (Your Safety Net)
6:04 Flatten the Nesting with Guard Clauses
11:26 Remove Unnecessary Try/Except Blocks
13:10 Simplify and Name Conditions
15:26 Simplify Loops and Comprehensions
16:28 Merge Duplicate Logic
19:07 Move Rules to Data
22:01 Final Thoughts

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From Spaghetti Code to Clean Python