Click: [Help needed] Implemented to print help message if no options were passed

[ShahriyarR]

Here is my simple code:

import click

def print_help(ctx, value):
    if value is False:
        return
    click.echo(ctx.get_help())
    ctx.exit()

@click.command()
@click.option('--dry_run', is_flag=True, help="Enable the dry run.")
@click.option('--prepare', is_flag=True, help="Prepare/recover backups.")
@click.option('--help', 
 is_flag=True,
 expose_value=False,
 is_eager=False,
 callback=print_help, 
 help="Print help message")
@click.pass_context
def all_procedure(ctx, dry_run, prepare):
    if (dry_run is False) and (prepare is False):
        print("No options passed!")
        print_help(ctx, value=True)

if __name__ == "__main__":
    all_procedure()

And it works.
Running without option:

$ python3 test_py.py
/home/shako/.local/lib/python3.5/site-packages/click/core.py:880: Warning: Invoked legacy parameter callback "<function print_help at 0x7f2482813048>".  The new signature for such callbacks starting with click 2.0 is (ctx, param, value).
  value, args = param.handle_parse_result(ctx, opts, args)
No options passed!
Usage: test_py.py [OPTIONS]

Options:
  --dry_run  Enable the dry run.
  --prepare  Prepare/recover backups.
  --help     Print help message

Running with --help:

$ python3 test_py.py --help
/home/shako/.local/lib/python3.5/site-packages/click/core.py:880: Warning: Invoked legacy parameter callback "<function print_help at 0x7f6df0bfa048>".  The new signature for such callbacks starting with click 2.0 is (ctx, param, value).
  value, args = param.handle_parse_result(ctx, opts, args)
Usage: test_py.py [OPTIONS]

Options:
  --dry_run  Enable the dry run.
  --prepare  Prepare/recover backups.
  --help     Print help message

Running with an option:

$ python3 test_py.py --dry_run
/home/shako/.local/lib/python3.5/site-packages/click/core.py:880: Warning: Invoked legacy parameter callback "<function print_help at 0x7f29c0e2a048>".  The new signature for such callbacks starting with click 2.0 is (ctx, param, value).
  value, args = param.handle_parse_result(ctx, opts, args)

The only remaining thing here is to overcome this Warning.
Any suggestion here? :)

[ShahriyarR]

To be clear.
The param should be passed from function.
The param type is:

param -> <click.core.Option object at 0x7fa40bbc61d0>

[ShahriyarR]

For now, done by passing None as param:

import click

def print_help(ctx, param, value):
    if value is False:
        return
    click.echo(ctx.get_help())
    ctx.exit()

@click.command()
@click.option('--dry_run', is_flag=True, help="Enable the dry run.")
@click.option('--prepare', is_flag=True, help="Prepare/recover backups.")
@click.option('--help', 
 is_flag=True,
 expose_value=False,
 is_eager=False,
 callback=print_help, 
 help="Print help message")
@click.pass_context
def all_procedure(ctx, dry_run, prepare):
    if (dry_run is False) and (prepare is False):
        print_help(ctx, None,  value=True)

if __name__ == "__main__":
    all_procedure()

shako@shako-localhost:~$ python3 test_py.py --help
Usage: test_py.py [OPTIONS]

Options:
  --dry_run  Enable the dry run.
  --prepare  Prepare/recover backups.
  --help     Print help message

shako@shako-localhost:~$ python3 test_py.py
Usage: test_py.py [OPTIONS]

Options:
  --dry_run  Enable the dry run.
  --prepare  Prepare/recover backups.
  --help     Print help message

[davidism]

Decision made to keep current "see --help" message in #502.