import typer app = typer.Typer() @app.command() def main(force: bool = typer.Option(False, "--force")): if force: print("Forcing operation") else: print("Not forcing") if __name__ == "__main__": app() ... // Check the help $ uv run python main.py --help // Notice there's only --force, we no longer have --no-force Usage: main.py [OPTIONS] Options: --force --help Show this message and exit.

August 11, 2025 - Boolean flags are options that don't need values. They're either on or off. Use typer.Option() with default values to create them.

Python 3.10+ - non-Annotated · Tip · Prefer to use the Annotated version if possible. import typer app = typer.Typer() @app.command() def main( name: str, lastname: str = typer.Option("", help="Last name of person to greet."), formal: bool = typer.Option(False, help="Say hi formally."), ): """ Say hi to 'name', optionally with a --lastname.

// Call it with CLI parameters $ uv run python main.py Camila --age 15 --height-meters 1.70 --female // All the data has the correct Python type name is Camila, of type: class 'str' --age is 15, of type: class 'int' --height-meters is 1.7, of type: class 'float' --female is True, of type: class 'bool' // And if you pass an incorrect type $ uv run python main.py Camila --age 15.3 Usage: main.py [OPTIONS] {name} Try "main.py --help" for help.

October 21, 2022 - import typer def main(force: bool = typer.Option(False, "--force", help="very long and verbose string here")): print(f"{force = }") if __name__ == "__main__": typer.run(main) ```sh ~  python foo.py --help Usage: foo.py [OPTIONS] ╭─ Options ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮ │ --force │ │ --install-completion Install completion for the current shell.

// check the help $ python main.py --help // Notice the <TEXT INTEGER BOOLEAN> Usage: main.py [OPTIONS] Options: --user <TEXT INTEGER BOOLEAN>... --help Show this message and exit. // Now try it $ python main.py --user Camila 50 yes The username Camila has 50 coins And this user is a wizard!

November 9, 2022 - Create a small typer script using the code mentioned above. ... Observe that the string optional parameter has a type of TEXT noted, and a listed default value in the main2 command. Observe that the boolean optional parameter has no type listed in the main command, and no default value listed, even though it has a default value of False set.

import typer from typing import List from pathlib import Path app = typer.Typer(name="demo", add_completion=False, help="This is a demo app.") @app.command() def talk(text: str = typer.Argument(..., help="The text to type."), repeat: int = typer.Option(1, help="Number of times to repeat."), loud: bool = typer.Option(False, is_flag=True)): """Talks some text below""" if loud: text = text.upper() for _ in range(repeat): print(text) if __name__ == "__main__": app() The talk command can be run in multiple ways now. python cli.py talk "hello there" python cli.py talk "hello there" --repeat 2 python cli.py talk "hello there" --loud python cli.py talk "hello there" --loud --repeat 3

Python 3.10+ import typer def main(name: str, lastname: str = "", formal: bool = False): """ Say hi to 'name', optionally with a --lastname. If --formal is used, say hi very formally. """ if formal: print(f"Good day Ms.

import typer app = typer.Typer() @app.command() def main(verbose: int = typer.Option(0, "--verbose", "-v", count=True)): print(f"Verbose level is {verbose}") if __name__ == "__main__": app() It means that the CLI option will be like a boolean flag, e.g. --verbose.

In this example above the CLI option --size is just a "flag" or "switch" that will contain a boolean value, True or False, depending on if it was added to the command or not. This one doesn't receive any values. But CLI options can also receive values like CLI arguments. You'll see how later. ... import typer def main(name: str, lastname: str, formal: bool = False): if formal: print(f"Good day Ms.

When you use CLI options with short names, you can put them together if they are just boolean flags, like --size or --human.

June 5, 2025 - import time from typing import Optional import typer from rich import print, progress, prompt app = typer.Typer() # Callback definition: https://typer.tiangolo.com/tutorial/commands/callback/ @app.callback(help="App callback definition") def callback( arg1: str = typer.Argument(..., help="Required argument for the entire app"), option1: bool = typer.Option(default=False, help="Optional argument for the entire app"), ) -> None: print(f"{arg1=}") print(f"{option1=}") # Required arguments: https://typer.tiangolo.com/tutorial/commands/arguments/…

import typer __version__ = "0.1.0" app = typer.Typer() def version_callback(value: bool): if value: print(f"Awesome CLI Version: {__version__}") raise typer.Exit() def name_callback(name: str): if name != "Camila": raise typer.BadParameter("Only Camila is allowed") return name @app.command() def main( name: str = typer.Option(..., callback=name_callback), version: bool | None = typer.Option(None, "--version", callback=version_callback), ): print(f"Hello {name}") if __name__ == "__main__": app() Then our CLI program could not work as expected in some cases as it is right now, because if we use --version after --name then the callback for --name will be processed before and we can get its error: $ python main.py --name Rick --version Only Camila is allowed Aborted!

Typer is a library for building CLI applications that users will love using and developers will love creating. Based on Python type hints.

May 12, 2025 - Typer’s design philosophy is all about writing less redundant code and focusing on business logic. You can define CLI parameters or options with a single function argument — whether it’s a string, integer, or boolean, Typer handles the conversion effortlessly through simple declarations.

Python 3.10+ from typing import Annotated import typer app = typer.Typer() @app.command() def create(username: str): print(f"Creating user: {username}") @app.command() def delete( username: str, force: Annotated[ bool, typer.Option(prompt="Are you sure you want to delete the user?") ], ): if force: print(f"Deleting user: {username}") else: print("Operation cancelled") @app.command() def delete_all( force: Annotated[ bool, typer.Option(prompt="Are you sure you want to delete ALL users?") ], ): if force: print("Deleting all users") else: print("Operation cancelled") @app.command() def init(): print("Initializing user database") if __name__ == "__main__": app() 🤓 Other versions and variants ·

June 23, 2023 - TypeIs can be used to annotate the return type of a user-defined type predicate function. TypeIs only accepts a single type argument. At runtime, functions marked this way should return a boolean and take at least one positional argument.

This tutorial shows you how to use Typer with all its features, step by step. Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific CLI needs. It is also built to work as a future reference so you can come back and see exactly what you need. All the code blocks can be copied and used directly (they are tested Python files).

July 3, 2026 - In this case, todo_id is a required instance of typer.Argument. Line 11 defines force as an option for the remove command. It’s a Boolean option that allows you to delete a to-do without confirmation.