Shared options and flags between commands

I have found a simple solution! I slightly edited the snippet from https://github.com/pallets/click/issues/108 :

import click


_cmd1_options = [
    click.option('--cmd1-opt')
]

_cmd2_options = [
    click.option('--cmd2-opt')
]


def add_options(options):
    def _add_options(func):
        for option in reversed(options):
            func = option(func)
        return func
    return _add_options


@click.group()
def group(**kwargs):
    pass


@group.command()
@add_options(_cmd1_options)
def cmd1(**kwargs):
    print(kwargs)


@group.command()
@add_options(_cmd2_options)
def cmd2(**kwargs):
    print(kwargs)


@group.command()
@add_options(_cmd1_options)
@add_options(_cmd2_options)
@click.option("--cmd3-opt")
def cmd3(**kwargs):
    print(kwargs)


if __name__ == '__main__':
    group()