Skip to content

CLI Options with Multiple Values

You can also declare a CLI option that takes several values of different types.

You can set the number of values and types to anything you want, but it has to be a fixed number of values.

For this, use the standard Python typing.Tuple:

from typing import Tuple

import typer


def main(user: Tuple[str, int, bool] = typer.Option((None, None, None))):
    username, coins, is_wizard = user
    if not username:
        typer.echo("No user provided")
        raise typer.Abort()
    typer.echo(f"The username {username} has {coins} coins")
    if is_wizard:
        typer.echo("And this user is a wizard!")


if __name__ == "__main__":
    typer.run(main)

Each of the internal types defines the type of each value in the tuple.

So:

user: Tuple[str, int, bool]

means that the parameter user is a tuple of 3 values.

  • The first value is a str.
  • The second value is an int.
  • The third value is a bool.

Later we do:

username, coins, is_wizard = user

If you hadn't seen that, it means that user is a tuple with 3 values, and we are assigning each of the values to a new variable:

  • The first value in the tuple user (a str) goes to the variable username.
  • The second value in the tuple user (an int) goes to the variable coins.
  • The third value in the tuple user (a bool) goes to the variable is_wizard.

So, this:

username, coins, is_wizard = user

is equivalent to this:

username = user[0]
coins = user[1]
is_wizard = user[2]

Tip

Notice that the default is a tuple with (None, None, None).

You cannot simply use None here as the default because Click doesn't support it.

Check it

Now let's see how this works in the terminal:

// check the help
$ python main.py --help

// Notice the <TEXT INTEGER BOOLEAN>
Usage: main.py [OPTIONS]

Options:
  --user <TEXT INTEGER BOOLEAN>...
  --install-completion            Install completion for the current shell.
  --show-completion               Show completion for the current shell, to copy it or customize the installation.
  --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!

// With other values
$ python main.py --user Morty 3 no

The username Morty has 3 coins

// Try with invalid values (not enough)
$ python main.py --user Camila 50

Error: --user option requires 3 arguments