In the following REPL example, foo is a required positional
parameter, while bar and baz have default values. We call the
function by passing positional values for foo (required) and bar
(overridden), but the function uses the default value for baz since
we don’t override that:
>>> def my_func(foo, bar='xyzzy', baz='quux'):
... print(foo, bar, baz)
...
>>> my_func('gralpy', 'plugh')
gralpy plugh quux