example_001_click.py

# coding=utf-8

# requirements.txt
# click


import click
import datetime


@click.group()
def cli():
    pass

@click.command()
@click.option('--date', default='now', help='The date format "yyyy-mm-dd"')
def get_weekday(date):
    if date == 'now':
        date = datetime.datetime.utcnow()
    else:
        date = datetime.datetime.strptime(date, '%Y-%m-%d')
    
    click.echo(date.strftime('%A'))

@click.command()
@click.option('--date1', help='The date format "yyyy-mm-dd"')
@click.option('--date2', help='The date format "yyyy-mm-dd"')
def delta_day(date1, date2):
    date1 = datetime.datetime.strptime(date1, '%Y-%m-%d')
    date2 = datetime.datetime.strptime(date2, '%Y-%m-%d')
    delta = date1 - date2 if date1 > date2 else date2 - date1
    click.echo(delta.days)

cli.add_command(get_weekday)
cli.add_command(delta_day)


if __name__ == '__main__':
    cli()