Merge pull request #6012 from jenshnielsen/typed_kwargs

Use typeddicts for better kwargs typing in Instrument classes

docs/changes/newsfragments/6012.breaking

@@ -0,0 +1,10 @@
+The keyword arguments expected to be passed to ``InstrumentBase`` and ``VisaInstrument`` subclasses are now
+documented as TypedDics classes that can be used to type `**kwargs` in the subclass constructors.
+See `Creating QCoDeS instrument drivers` for usage examples.
+
+This also means that the these arguments **must** be passed as keyword arguments, and not as positional arguments.
+This specifically includeds passing ``label`` and ``metadata`` to direct subclasses of ``Instrument`` as well as
+``terminator`` to subclasses of ``VisaInstrument``.
+
+All drivers shipping with qcodes for Vendors from A-K have been updated.
+The remaining drivers will be updated in a subsequent pull request.

docs/examples/writing_drivers/A-ParameterWithSetpoints-Example-with-Dual-Setpoints.ipynb

@@ -15,24 +15,12 @@
    "cell_type": "code",
    "execution_count": 1,
    "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Logging hadn't been started.\n",
-      "Activating auto-logging. Current session state plus future input saved.\n",
-      "Filename       : C:\\Users\\jenielse\\.qcodes\\logs\\command_history.log\n",
-      "Mode           : append\n",
-      "Output logging : True\n",
-      "Raw input log  : False\n",
-      "Timestamping   : True\n",
-      "State          : active\n",
-      "Qcodes Logfile : C:\\Users\\jenielse\\.qcodes\\logs\\220617-25816-qcodes.log\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
+    "from typing import TYPE_CHECKING\n",
+    "\n",
+    "if TYPE_CHECKING:\n",
+    "    from typing_extensions import Unpack\n",
     "import os\n",
     "\n",
     "import numpy as np\n",
@@ -44,7 +32,7 @@
     "    load_or_create_experiment,\n",
     "    plot_dataset,\n",
     ")\n",
-    "from qcodes.instrument import Instrument\n",
+    "from qcodes.instrument import Instrument, InstrumentBaseKWArgs\n",
     "from qcodes.parameters import Parameter, ParameterWithSetpoints"
    ]
   },
@@ -111,7 +99,7 @@
     "\n",
     "class OzzyLowScope(Instrument):\n",
     "\n",
-    "    def __init__(self, name, **kwargs):\n",
+    "    def __init__(self, name: str, **kwargs: \"Unpack[InstrumentBaseKWArgs]\"):\n",
     "\n",
     "        super().__init__(name, **kwargs)\n",
     "\n",
@@ -494,7 +482,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.13"
+   "version": "3.12.1"
   },
   "toc": {
    "base_numbering": 1,

docs/examples/writing_drivers/Creating-Instrument-Drivers.ipynb

@@ -18,12 +18,23 @@
     "import ctypes  # only for DLL-based instrument\n",
     "import sys\n",
     "import time\n",
-    "from typing import Any\n",
+    "from typing import TYPE_CHECKING, Any\n",
+    "\n",
+    "if TYPE_CHECKING:\n",
+    "    from typing_extensions import (\n",
+    "        Unpack,  # can be imported from typing if python >= 3.12\n",
+    "    )\n",
     "\n",
     "import numpy as np\n",
     "\n",
     "from qcodes import validators as vals\n",
-    "from qcodes.instrument import Instrument, InstrumentChannel, VisaInstrument\n",
+    "from qcodes.instrument import (\n",
+    "    Instrument,\n",
+    "    InstrumentBaseKWArgs,\n",
+    "    InstrumentChannel,\n",
+    "    VisaInstrument,\n",
+    "    VisaInstrumentKWArgs,\n",
+    ")\n",
     "from qcodes.instrument_drivers.AlazarTech.utils import TraceParameter\n",
     "from qcodes.parameters import ManualParameter, MultiParameter, Parameter"
    ]
@@ -196,10 +207,17 @@
     "    \"\"\"\n",
     "\n",
     "    # all instrument constructors should accept **kwargs and pass them on to\n",
-    "    # super().__init__\n",
-    "    def __init__(self, name, address, **kwargs):\n",
-    "        # supplying the terminator means you don't need to remove it from every response\n",
-    "        super().__init__(name, address, terminator=\"\\r\", **kwargs)\n",
+    "    # super().__init__ By using Unpack[VisaKWArgs] we ensure that the instrument class takes exactly the same keyword args as the base class\n",
+    "    # Visa instruments are also required to take name, address and terminator as arguments.\n",
+    "    # name and address should be positional arguments. To overwrite the default terminator or timeout\n",
+    "    # the attribute default_terminator or default_timeout should be defined as a class attribute in the instrument class\n",
+    "    # as shown below for the default_terminator\n",
+    "    default_terminator = \"\\r\"\n",
+    "\n",
+    "    def __init__(\n",
+    "        self, name: str, address: str, **kwargs: \"Unpack[VisaInstrumentKWArgs]\"\n",
+    "    ):\n",
+    "        super().__init__(name, address, **kwargs)\n",
     "\n",
     "        self.attenuation = Parameter(\n",
     "            \"attenuation\",\n",
@@ -266,20 +284,21 @@
     "    SMUA and SMUB.\n",
     "    \"\"\"\n",
     "\n",
-    "    def __init__(self, parent: Instrument, name: str, channel: str) -> None:\n",
+    "    def __init__(self, parent: Instrument, name: str, channel: str, **kwargs: \"Unpack[InstrumentBaseKWArgs]\") -> None:\n",
     "        \"\"\"\n",
     "        Args:\n",
     "            parent: The Instrument instance to which the channel is\n",
     "                to be attached.\n",
     "            name: The 'colloquial' name of the channel\n",
     "            channel: The name used by the Keithley, i.e. either\n",
     "                'smua' or 'smub'\n",
+    "            **kwargs: Forwarded to base class.\n",
     "        \"\"\"\n",
     "\n",
     "        if channel not in [\"smua\", \"smub\"]:\n",
     "            raise ValueError('channel must be either \"smub\" or \"smua\"')\n",
     "\n",
-    "        super().__init__(parent, name)\n",
+    "        super().__init__(parent, name, **kwargs)\n",
     "        self.model = self._parent.model\n",
     "\n",
     "        self.volt = Parameter(\n",
@@ -342,15 +361,16 @@
     "    This is the qcodes driver for the Keithley2600 Source-Meter series,\n",
     "    tested with Keithley2614B\n",
     "    \"\"\"\n",
+    "    default_terminator = \"\\n\"\n",
     "\n",
-    "    def __init__(self, name: str, address: str, **kwargs) -> None:\n",
+    "    def __init__(self, name: str, address: str, **kwargs: \"Unpack[VisaInstrumentKWArgs]\") -> None:\n",
     "        \"\"\"\n",
     "        Args:\n",
     "            name: Name to use internally in QCoDeS\n",
     "            address: VISA ressource address\n",
     "            **kwargs: kwargs are forwarded to the base class.\n",
     "        \"\"\"\n",
-    "        super().__init__(name, address, terminator=\"\\n\", **kwargs)\n",
+    "        super().__init__(name, address, **kwargs)\n",
     "\n",
     "        model = self.ask(\"localnode.model\")\n",
     "\n",
@@ -416,7 +436,7 @@
     "class AlazarTechATS(Instrument):\n",
     "    dll_path = \"C:\\\\WINDOWS\\\\System32\\\\ATSApi\"\n",
     "\n",
-    "    def __init__(self, name, system_id=1, board_id=1, dll_path=None, **kwargs):\n",
+    "    def __init__(self, name, system_id=1, board_id=1, dll_path=None, **kwargs: \"Unpack[InstrumentBaseKWArgs]\"):\n",
     "        super().__init__(name, **kwargs)\n",
     "\n",
     "        # connect to the DLL\n",
@@ -471,7 +491,7 @@
     "class SomeDLLInstrument(Instrument):\n",
     "    dll_path = \"C:\\\\WINDOWS\\\\System32\\\\ATSApi\"\n",
     "\n",
-    "    def __init__(self, name, dll_path=None, **kwargs):\n",
+    "    def __init__(self, name, dll_path=None, **kwargs: \"Unpack[InstrumentBaseKWArgs]\"):\n",
     "        super().__init__(name, **kwargs)\n",
     "\n",
     "        if sys.platform != \"win32\":\n",
@@ -557,7 +577,7 @@
     "    This is a virtual driver only and will not talk to your instrument.\n",
     "    \"\"\"\n",
     "\n",
-    "    def __init__(self, name, **kwargs):\n",
+    "    def __init__(self, name: str, **kwargs: \"Unpack[InstrumentBaseKWArgs]\"):\n",
     "        super().__init__(name, **kwargs)\n",
     "\n",
     "        # ManualParameter has an \"initial_value\" kwarg, but if you use this\n",

docs/examples/writing_drivers/Creating-Simulated-PyVISA-Instruments.ipynb

@@ -66,20 +66,26 @@
     }
    ],
    "source": [
+    "from typing import TYPE_CHECKING\n",
+    "\n",
     "import numpy as np\n",
     "\n",
     "import qcodes.validators as vals\n",
-    "from qcodes.instrument.visa import VisaInstrument\n",
+    "from qcodes.instrument.visa import VisaInstrument, VisaInstrumentKWArgs\n",
+    "\n",
+    "if TYPE_CHECKING:\n",
+    "    from typing_extensions import Unpack\n",
     "\n",
     "\n",
     "class Weinschel8320(VisaInstrument):\n",
     "    \"\"\"\n",
     "    QCoDeS driver for the stepped attenuator\n",
     "    Weinschel is formerly known as Aeroflex/Weinschel\n",
     "    \"\"\"\n",
+    "    default_terminator = \"\\r\"\n",
     "\n",
-    "    def __init__(self, name, address, **kwargs):\n",
-    "        super().__init__(name, address, terminator='\\r', **kwargs)\n",
+    "    def __init__(self, name: str, address: str, **kwargs: 'Unpack[VisaInstrumentKWArgs]'):\n",
+    "        super().__init__(name, address, **kwargs)\n",
     "\n",
     "        self.add_parameter('attenuation', unit='dB',\n",
     "                           set_cmd='ATTN ALL {:02.0f}',\n",

src/qcodes/instrument/__init__.py

@@ -17,18 +17,20 @@
 
 from .channel import ChannelList, ChannelTuple, InstrumentChannel, InstrumentModule
 from .instrument import Instrument, find_or_create_instrument
-from .instrument_base import InstrumentBase
+from .instrument_base import InstrumentBase, InstrumentBaseKWArgs
 from .ip import IPInstrument
-from .visa import VisaInstrument
+from .visa import VisaInstrument, VisaInstrumentKWArgs
 
 __all__ = [
     "ChannelList",
     "ChannelTuple",
     "IPInstrument",
     "Instrument",
     "InstrumentBase",
+    "InstrumentBaseKWArgs",
     "InstrumentChannel",
     "InstrumentModule",
     "VisaInstrument",
+    "VisaInstrumentKWArgs",
     "find_or_create_instrument",
 ]

src/qcodes/instrument/channel.py

@@ -19,7 +19,10 @@
 from .instrument_base import InstrumentBase
 
 if TYPE_CHECKING:
+    from typing_extensions import Unpack
+
     from .instrument import Instrument
+    from .instrument_base import InstrumentBaseKWArgs
 
 
 class InstrumentModule(InstrumentBase):
@@ -33,15 +36,14 @@ class InstrumentModule(InstrumentBase):
     Args:
         parent: The instrument to which this module should be
           attached.
-
         name: The name of this module.
+        **kwargs: Forwarded to the base class.
 
     """
 
-    def __init__(self,
-                 parent: InstrumentBase,
-                 name: str,
-                 **kwargs: Any) -> None:
+    def __init__(
+        self, parent: InstrumentBase, name: str, **kwargs: Unpack[InstrumentBaseKWArgs]
+    ) -> None:
         # need to specify parent before `super().__init__` so that the right
         # `full_name` is available in that scope. `full_name` is used for
         # registering the filter for the log messages. It is composed by

src/qcodes/instrument/instrument.py

@@ -9,15 +9,14 @@
 from qcodes.utils import strip_attrs
 from qcodes.validators import Anything
 
-from .instrument_base import InstrumentBase
+from .instrument_base import InstrumentBase, InstrumentBaseKWArgs
 from .instrument_meta import InstrumentMeta
 
 if TYPE_CHECKING:
-    from collections.abc import Mapping
+    from typing_extensions import Unpack
 
     from qcodes.logger.instrument_logger import InstrumentLoggerAdapter
 
-
 log = logging.getLogger(__name__)
 
 
@@ -66,16 +65,11 @@ class Instrument(InstrumentBase, metaclass=instrument_meta_class):
     _type: type[Instrument] | None = None
     _instances: weakref.WeakSet[Instrument] = weakref.WeakSet()
 
-    def __init__(
-        self,
-        name: str,
-        metadata: Mapping[Any, Any] | None = None,
-        label: str | None = None,
-    ) -> None:
+    def __init__(self, name: str, **kwargs: Unpack[InstrumentBaseKWArgs]) -> None:
 
         self._t0 = time.time()
 
-        super().__init__(name=name, metadata=metadata, label=label)
+        super().__init__(name=name, **kwargs)
 
         self.add_parameter("IDN", get_cmd=self.get_idn, vals=Anything())
 

src/qcodes/instrument/instrument_base.py

@@ -7,6 +7,7 @@
 from typing import TYPE_CHECKING, Any, ClassVar
 
 import numpy as np
+from typing_extensions import TypedDict
 
 from qcodes.logger import get_instrument_logger
 from qcodes.metadatable import Metadatable, MetadatableWithName
@@ -16,6 +17,8 @@
 if TYPE_CHECKING:
     from collections.abc import Callable, Mapping, Sequence
 
+    from typing_extensions import NotRequired
+
     from qcodes.instrument.channel import ChannelTuple, InstrumentModule
     from qcodes.logger.instrument_logger import InstrumentLoggerAdapter
 
@@ -24,6 +27,24 @@
 log = logging.getLogger(__name__)
 
 
+class InstrumentBaseKWArgs(TypedDict):
+    """
+    This TypedDict defines the type of the kwargs that can be passed to the InstrumentBase class.
+    A subclass of VisaInstrument should take ``**kwargs: Unpack[InstrumentBaseKWArgs]`` as input
+    and forward this to the super class to ensure that it can accept all the arguments defined here.
+    """
+
+    metadata: NotRequired[Mapping[Any, Any] | None]
+    """
+    Additional static metadata to add to this
+    instrument's JSON snapshot.
+    """
+    label: NotRequired[str | None]
+    """
+    Nicely formatted name of the instrument; if None,
+    the ``name`` is used.
+    """
+
 class InstrumentBase(MetadatableWithName, DelegateAttributes):
     """
     Base class for all QCodes instruments and instrument channels