juice500ml/click

Click is a Python library that makes it easy to build command-line programs, the kind of tools you run in a terminal with typed commands rather than clicking buttons. Instead of wrestling with complicated code to parse what users type, Click handles that for you and lets you focus on what your program actually does. Think of it like a framework for CLIs. If you've ever used a command like git commit -m "message" or npm install package-name, those are command-line interfaces. Building one traditionally requires a lot of boilerplate, code that defines what arguments the user can pass, what flags are available, error handling, and so on. Click automates most of that. You write simple Python functions and decorate them with Click's syntax to say "this function is a command" and "this parameter is a flag." Click then handles parsing user input, validating it, and even generating help text automatically. The library is built around composability, which means you can nest commands within commands without things getting messy. You might have a main command like myapp with subcommands like myapp user create or myapp config set. Click also supports lazy loading, so if your program has many subcommands, you don't have to load them all at startup, they load only when needed. This keeps things fast and lightweight. Who uses this? Developers building tools they want to share with others, internal scripts, package managers, deployment tools, monitoring utilities, or anything that needs a clean command-line interface. If you're a founder or PM building developer tools, your engineers likely use Click to ensure your CLI feels polished and professional. It's stable and widely used in the Python ecosystem, so you can rely on it not changing underneath you unexpectedly.