Python Keyword-Only Parameter

def configure_server(host, port, *, secure, timeout=30):
    # 'host' and 'port' can be positional or keyword.
    # 'secure' and 'timeout' are strictly keyword-only.
    pass


# Valid Invocation
configure_server("127.0.0.1", 8080, secure=True)
configure_server("127.0.0.1", 8080, secure=True, timeout=60)


# Invalid Invocation: Raises TypeError (takes 2 positional arguments but 3 were given)
configure_server("127.0.0.1", 8080, True) 

def concatenate_strings(*strings, delimiter=","):
    # 'strings' captures all positional arguments as a tuple.
    # 'delimiter' is keyword-only.
    return delimiter.join(strings)


# Valid Invocation
concatenate_strings("apple", "banana", "cherry", delimiter="|")


# Syntactically valid, but "->" is absorbed into the *strings tuple, 

# leaving 'delimiter' at its default value.
concatenate_strings("apple", "banana", "cherry", "->") 

# Comprehensive Signature Example
def complex_function(pos_only, /, standard, *args, kw_only1, kw_only2="default", **kwargs):
    pass