I&#x27;m looking for a new CLI library.<p>I like Click because it does very simple things very well.  It gets hairy when you want to build more complex CLIs.  For example, value options and validators don&#x27;t play nicely because Click doesn&#x27;t distinguish between the absence of a value and an invalid value, so you wind up dropping Click features and rewriting your own plumbing for that kind of stuff.  The alternative is writing a more verbose CLI grammar, which leads to a really clunky UI.