CODEWITHSUNDEEP
pythonpython-click
wonder
wonder

Reputation: 903

Python Click options - Avoid taking multiple times the same option if the parameter multiple is not passed

I am using python click for my development purposes. I have the following command line with one option:

add student -n xx -n yy

code :

@click.group()
@click.version_option("Development", help="Echo version and exit")
@click.help_option(help = "Use this on subcommands for more information")
def cli():
    '''Add a student/teacher/principal'''

@cli.command()
@click.option('--name', '-n', required=True, help='Specify the name of the student')
def student(name):
    '''Add a Student'''

While using the above command line, how I am able to use the same option multiple times?? I see that the value for name is yy. How can I avoid taking multiple -n if multiple is not true??

Thank you.

Upvotes: 2

Views: 3260

Answers (2)

user3137329
user3137329

Reputation:

Use the kwargs

multiple=True

Running this

import click


@click.group()
@click.version_option("Development", help="Echo version and exit")
@click.help_option(help="Use this on subcommands for more information")
def cli():
    """Add a student/teacher/principal"""


def validate_student(ctx, param, value):
    try:
        if len(value) > 1:
            raise ValueError
        else:
            return value
    except ValueError:
        raise click.BadParameter('Students should be not more than 1')


@cli.command()
@click.option('--name', '-n', required=True, multiple=True, help='Specify the name of the student',
              callback=validate_student)
def student(name):
    """Add a Student"""
    print(name)


if __name__ == "__main__":
    student()

Gives me this

$ python3 add.py -n xx -n yy
    Usage: add.py [OPTIONS]

Error: Invalid value for "--name" / "-n": Students should be not more than 1

Process finished with exit code 0

But passing only 1 param returns:

$ python3 add.py -n xx
('xx',)

This is documented here: http://click.pocoo.org/5/options/#multi-value-options and here http://click.pocoo.org/5/options/#callbacks-for-validation

Upvotes: 1

RatDon
RatDon

Reputation: 3543

You can use multiple with a tweak. Make the multiple=True. Accept the multiple values. And throw error if there are more than one item.

def check_multiple(ctx, param, value):
    if len(name) > 1:
        click.echo('Multiple options are not accepted!')
        ctx.abort()
@cli.command()
@click.option('--name', '-n', required=True, multiple=True, callback=check_multiple, help='Specify the name of the student')
def student(name):
    ''' '''

Since, I don't have a current setup, the above code is not tested; Derived from the documentation.

Upvotes: 2

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