def function(positional1, positional2, keyword1=None, keyword2=None):
    print(positional1, positional2)
    print(keyword1, keyword2)

function(1,2)
function(1,2,3,4)

function(1,2,keyword2=5)

try:
    function(1,keyword2=5)
except as exception:
    print(exception.arg)

try:
    function(1,2,positional1=4)
except as exception:
    print(exception.arg)

try:
    function(1,2,keyword2=None,keyword2=5)
except as exception:
    print(exception.arg)

function(1,keyword2=4,positional2="abc")

try:
    function(1,keyword2=4,keyword1=5,positional1="nope")
except as exception:
    print(exception.arg)