Most CLI tools fail not because they lack power — but because they accept garbage input. Today you learn to prevent that. You’ll tame user chaos with: * ✅ nargs for multiple values * ✅ choices to limit options * ✅ type for automatic conversion * ✅ required and default to guide logic * ✅ Custom actions — your CLI, your

Your CLI isn’t just a script anymore — it’s a command suite. This lesson takes you beyond single-command logic and into the world of: * ✅ Organized --help output * ✅ Input safety with mutually exclusive options * ✅ Scalable command families like git add, git commit, git push Grouping Arguments — Clean Up Your Help