varnames.py

import dis, sys

def varnames():
    frame = sys._getframe(1)
    instrs = dis.get_instructions(frame.f_code)
    instr = next(instr for instr in instrs if instr.offset > frame.f_lasti)
    match instr.opname:
        case "STORE_FAST" | "STORE_GLOBAL" | "STORE_NAME":
            return instr.argval
        case "STORE_FAST_LOAD_FAST":
            return instr.argval[0]
        case "LOAD_FAST" | "LOAD_GLOBAL" | "LOAD_NAME":
            instr = next(instrs)
            match instr.opname:
                case "STORE_ATTR":
                    return instr.argval
                case _:
                    raise NotImplementedError(repr(instr))
        case "UNPACK_SEQUENCE":
            variables = []
            num_variables = instr.arg
            while len(variables) < num_variables:
                instr = next(instrs)
                match instr.opname:
                    case "STORE_FAST" | "STORE_GLOBAL" | "STORE_NAME":
                        variables.append(instr.argval)
                    case "STORE_FAST_LOAD_FAST":
                        variables.append(instr.argval[0])
                        if len(variables) < num_variables:
                            instr = next(instrs)
                            match instr.opname:
                                case "STORE_ATTR":
                                    variables.append(instr.argval)
                                case _:
                                    raise NotImplementedError(repr(instr))
                    case "STORE_FAST_STORE_FAST":
                        variables.extend(instr.argval)
                    case "LOAD_FAST" | "LOAD_GLOBAL" | "LOAD_NAME":
                        instr = next(instrs)
                        match instr.opname:
                            case "STORE_ATTR":
                                variables.append(instr.argval)
                            case _:
                                raise NotImplementedError(repr(instr))
                    case _:
                        raise NotImplementedError(repr(instr))
            return variables
        case _:
            raise NotImplementedError(repr(instr))

x = varnames()
assert x == "x"

x, y, z = varnames()
assert (x, y, z) == ("x", "y", "z")

w = varnames(); x = x
assert w == "w"

x, y, z = varnames(); w = w
assert (x, y, z) == ("x", "y", "z")

class Test:
    def __init__(self):
        self.x = varnames()
        assert self.x == "x"

        self.x, self.y, self.z = varnames()
        assert (self.x, self.y, self.z) == ("x", "y", "z")

        a, self.b, c, self.d, e = varnames(); a = a
        assert (a, self.b, c, self.d, e) == ("a", "b", "c", "d", "e")

obj = Test()

obj.i = varnames()
assert obj.i == "i"

obj.j, obj.k = varnames()
assert (obj.j, obj.k) == ("j", "k")

def test():
    x = varnames()
    assert x == "x"

    x, y, z = varnames()
    assert (x, y, z) == ("x", "y", "z")

    w = varnames(); x = x
    assert w == "w"

    x, y, z = varnames(); w = w
    assert (x, y, z) == ("x", "y", "z")

    obj.p = varnames()
    assert obj.p == "p"

    obj.q, obj.r = varnames()
    assert (obj.q, obj.r) == ("q", "r")

test()