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:

Python 3.7+Python 3.7+ non-Annotated

from typing import Tuple

import typer
from typing_extensions import Annotated


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


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

Tip

Prefer to use the Annotated version if possible.

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:
        print("No user provided")
        raise typer.Abort()
    print(f"The username {username} has {coins} coins")
    if is_wizard:
        print("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 &lt;TEXT INTEGER BOOLEAN&gt;
Usage: main.py [OPTIONS]

Options:
  --user &lt;TEXT INTEGER BOOLEAN&gt;...
  --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: Option '--user' requires 3 arguments