Hello, Nu

Run your first Nu program: a tree that prints "hello" once a second.

Install Nu first: see Install.

import asyncio
import nu

tree = nu.ForeverDo(nu.print("hello") >> nu.Delay(1.0))

asyncio.run(nu.arun(tree))

Save as hello.py, then run:

python hello.py

You see "hello" print once a second, forever. Press Ctrl+C to stop.

hello
hello
hello

What just happened

You built a tree of three Nu operations: ForeverDo loops its body, print writes a line, Delay waits. Nothing ran while you built it. nu.arun executed the tree.

>> composes left to right. So each loop iteration prints, then waits a second, then goes again.

That is the whole Nu model in miniature. You describe a tree, Nu runs it.

Next

Add state and a browser dashboard: Your first app.