<s>[INST] Can a variable number of arguments be passed to a function? In a similar way to using varargs in C or C++:
fn(a, b)
fn(a, b, c, d, ...)

 [/INST] Yes.
This is simple and works if you disregard keyword arguments:
def manyArgs(*arg):
  print "I was called with", len(arg), "arguments:", arg

>>> manyArgs(1)
I was called with 1 arguments: (1,)
>>> manyArgs(1, 2,3)
I was called with 3 arguments: (1, 2, 3)

As you can see, Python will give you a single tuple with all the arguments.
For keyword arguments you need to accept those as a separate actual argument, as shown in Skurmedel's answer.
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