A demo if __name__ == "__main__": block in a module other code imports; an examples or demo folder nobody asked for

Code nobody needs: one of the ways AI coding agents bloat software, from lessloc's pattern catalog. lessloc catches it as demo-code and new-folder.

What makes a demo __main__ block or demo folder nobody asked for a bad practice?

The standard that calls it a bad practice: YAGNI.

What does lessloc do about a demo __main__ block or demo folder nobody asked for?

lessloc catches it as demo-code and new-folder.

• demo-code (tier 2): An example or demo block, such as if __name__ == "__main__":, in a module other code imports.
• new-folder (tier 2): A new folder with one or two entries, or an examples or demo folder nobody asked for.

Related patterns

The other patterns in Code nobody needs:

• Options, flags, parameters or config for needs nobody named: lessloc gives every session a rule against it and catches it as mode-flag.
• An interface or abstract class with one implementation: lessloc catches it as single-impl.
• Wrappers that only forward; barrel files that only re-export: lessloc catches it as wrapper.
• A new function or import that nothing calls or tests: lessloc catches it as unused (ruff adds unused variables).
• Obsolete code kept behind a guard or flag instead of deleted: lessloc gives every session the rule: delete what the change makes dead.
• Tombstones: lessloc catches it as history.
• Stubs and fake success: lessloc catches it as stub; it asks to finish the code or to tell the user what is not real yet.
• Placeholders: # ... existing code ..., "your code here": lessloc catches it as placeholder and refuses it before it lands.
• Commented-out code: lessloc catches it as commented-out and refuses it before it lands.
• Debug leftovers: lessloc catches it as debug-leftover.
• Hand-written boilerplate a language feature writes: lessloc catches it as simpler.
• A one-line helper used once: lessloc catches it as single-use.
• TODO and FIXME left behind: lessloc catches it as todo; it asks to finish the work, or to record known debt as shortcut: and tell the user.