How to define a function/method in Rust which accepts at most 2 positional arguments?

[lycantropos]

What is an idiomatic way of defining a Rust function which accepts limited number of positional arguments?
E.g., I want to be able to write something like

>>> from rust_module import foo
>>> foo()
>>> foo(1)
>>> foo(1, 2)
>>> foo(1, 2, 3)
Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: foo() takes from 0 to 2 positional arguments but 3 were given

In Python C API we can use PyArg_ParseTuple, but are there any examples of how to do it properly in PyO3?

[birkenfeld]

Like in Python - just take two arguments with one having a default value.

Or take *args and extract the contents yourself, this is closer to the C and using PyArg_UnpackTuple (which you probably meant).