PEP 3102

#!/usr/bin/env python3
"""Demonstrate some new function calling syntax and behaviour in Python 3.

See `PEP 3102 <https://www.python.org/dev/peps/pep-3102/>`_.
"""


def main():
    """Demonstrate how to use :func:`foo` and :func:`bar`."""
    foo(                      )
    foo(        keyword='boop')
    foo('beep'                )
    foo('beep', keyword='boop')
    # bar(    1,     2)  # disallowed
    bar(    1, two=2)
    bar(one=1, two=2)


def foo(*positional, keyword=None):
    """Varargs may appear before default arguments."""
    print(positional, keyword)


def bar(one, *, two):
    """Arguments may be denoted as keyword only."""
    print(one, two)


if __name__ == '__main__':
    exit(main())