How to show/hide input option based on the first input?

Question

I'm writing a command-line tool using Python Click package.

For the user input, I want to show/hide the next input option based on the first input.

Here is the sample code:

import click


@click.command()
@click.option('--user/--no-user', prompt='do you want to add user?')
@click.option('--new-user', prompt='add user')
def add_user(user, new_user):
    print(user)
    print(new_user)


add_user()

I want to show 2nd prompt('--new-user') only if the user type yes for the first input('--user/--no-user').

Any help how can I do this? Thanks in advance.

Answer 1

You would have to use a custom callback:

import click

def prompt_user(ctx, param, user):
    new_user = None
    if user:
        new_user = click.prompt('username')
    return (user, new_user)


@click.command()
@click.option('--user/--no-user', prompt='do you want to add user?', callback=prompt_user)
def add_user(user):
    user, new_user = user
    print(user)
    print(new_user)

if __name__ == '__main__':
    add_user()

$ python3.8 user.py
do you want to add user? [y/N]: y
username: no
True
no
$ python3.8 user.py
do you want to add user? [y/N]: N
False
None

Note that prompt_user returns a tuple of two values. So the line user, new_user = user sets user equal to the first value and new_user to the second. See this link for more explanation.