How Many Arguments?

Create a function that takes a function func and counts its arguments. Examining a function's bytecode using __code__ is disabled.

Examples

num_args(lambda: "") ➞ 0

num_args(lambda x: "") ➞ 1

num_args(lambda x, y: "") ➞ 2

Notes

• All random test function expressions will be constructed using +, -, *, and /.
• None of the parameters of func will have default values.
• All functions will be converted to a custom class object to avoid use of __code__.
• If disabling __code__ or removing function functionality is too harsh, feel free to leave a comment.