Writing Simple Python CLI using Click

Python Click package enables you to create CLI tools easily. With this, you can focus on core logic while Click does the flag parsing and validations.

Creating a command is as simple as:

import click

@click.command() # Creates a click command
@click.option(   # Check out click's documentation to see all the options
    "--input",
    required=True,
    help = "Some input that you must provide",
)
def cli(input):  # The options becomes parameters to the method
    # You can now use input to do something
    print(f'Hello {input}')

if __name__ == "__main__":
    # Name of this method doesn't matter. Command name is derived from
    # the file name.
    cli()

Click has good documentation. Have a look.