Katharos - Functional programming and CSP-style concurrency for Python

Show HN: Katharos Functional programming and CSP-style concurrency for Python

Katharos is a Python library that brings functional programming and message-passing concurrency together. It provides algebraic abstractions like Functor, Applicative, Monad, Semigroup, and Monoid, along with concrete types such as Maybe, Result, ImmutableList, and IO. The library models errors, effects, and concurrent communication as composable, type-safe values, eliminating scattered None checks and nested try/except blocks. Its Go-style CSP concurrency uses typed channels and returns Result values, so channel closure is handled as a value, not an exception. With do-notation for monadic code and structured concurrency scopes, Katharos simplifies complex logic and improves code reliability.