CLIs in Python

Python is quite good for building CLI apps. With Typer we can easily define commands and their arguments using type annotations.

Here’s an example from a Distributed Systems assignment from university:

from typing import Annotated
 
from typer import Option, Typer
 
from trabalho_1.application import Application
from trabalho_1.server import Server
 
app = Typer()
 
topic = "room"
 
 
@app.command(help="Run the client GUI application.")
def client(
    broker_address: Annotated[
        str, Option(help="The IP address or hostname of the message broker.")
    ] = "127.0.0.1"
):
    application = Application(broker_address=broker_address, topic=topic)
    application.start()
 
 
@app.command(help="Run the message broker server.")
def server():
    server = Server(topic=topic)
    server.bind()
    server.start()

There’s also rich to print rich text in the terminal. The combination of those tools and Python’s ease of use make for a very nice mix for building CLI apps. My only concern is with the distribution of such CLI, given that we cannot generate a static binary like in Go.