Avoid mutable default arguments

[DimitriPapadopoulos]

• Common Gotchas | The Hitchhiker’s Guide to Python
• Python Pitfall: Mutable Default Arguments
• Python Mutable Defaults Are The Source of All Evil

[DimitriPapadopoulos]

I believe this is not needed here, but you may change back None → [] at the beginning of the modified functions:

def modified_function(machine_code=None):
    machine_code = machine_code or []

The above will change machine_code to [] not only if it is None, but also False or 0. But I think it is OK in this context.

[DimitriPapadopoulos]

And argtypes=() is OK because tuples are not mutable.

[workhorsy]

I want to merge this later, as it changes the API, and will require me to bump the version up to 10.0.0.