Merge pull request #6073 from qutech/bugfix/multi_channel_instrument_…

…parameter_setter

Accept sequences of values for setting MultiChannelInstrumentParameter

docs/changes/newsfragments/6073.improved

@@ -0,0 +1 @@
+Accept sequences of values for setting `MultiChannelInstrumentParameter` s. Previously, the behavior was inconsistent since `param.set(param.get())` would error.

src/qcodes/parameters/multi_channel_instrument_parameter.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import logging
+import sys
 from typing import TYPE_CHECKING, Any, Generic, TypeVar
 
 from .multi_parameter import MultiParameter
@@ -12,6 +14,7 @@
     from .parameter_base import ParamRawDataType
 
 InstrumentModuleType = TypeVar("InstrumentModuleType", bound="InstrumentModule")
+_LOG = logging.getLogger(__name__)
 
 
 class MultiChannelInstrumentParameter(MultiParameter, Generic[InstrumentModuleType]):
@@ -45,16 +48,35 @@ def get_raw(self) -> tuple[ParamRawDataType, ...]:
         """
         return tuple(chan.parameters[self._param_name].get() for chan in self._channels)
 
-    def set_raw(self, value: ParamRawDataType) -> None:
+    def set_raw(self, value: ParamRawDataType | Sequence[ParamRawDataType]) -> None:
         """
-        Set all parameters to this value.
+        Set all parameters to this/these value(s).
 
         Args:
-            value: The value to set to. The type is given by the
+            value: The value(s) to set to. The type is given by the
                 underlying parameter.
         """
-        for chan in self._channels:
-            getattr(chan, self._param_name).set(value)
+        try:
+            for chan in self._channels:
+                getattr(chan, self._param_name).set(value)
+        except Exception as err:
+            try:
+                # Catch wrong length of value before any setting is done
+                value_list = list(value)
+                if len(value_list) != len(self._channels):
+                    raise ValueError
+                for chan, val in zip(self._channels, value_list):
+                    getattr(chan, self._param_name).set(val)
+            except (TypeError, ValueError):
+                note = (
+                    "Value should either be valid for a single parameter of the channel list "
+                    "or a sequence of valid values of the same length as the list."
+                )
+                if sys.version_info >= (3, 11):
+                    err.add_note(note)
+                else:
+                    _LOG.error(note)
+                raise err from None
 
     @property
     def full_names(self) -> tuple[str, ...]:

tests/parameter/test_multi_channel_instrument_parameter.py

@@ -0,0 +1,53 @@
+import sys
+from typing import TYPE_CHECKING
+
+import pytest
+
+from qcodes.instrument_drivers.mock_instruments import DummyChannelInstrument
+
+if TYPE_CHECKING:
+    from collections.abc import Generator
+
+
+@pytest.fixture
+def dummy_channel_instrument() -> "Generator[DummyChannelInstrument, None, None]":
+    instrument = DummyChannelInstrument(name="testdummy")
+    try:
+        yield instrument
+    finally:
+        instrument.close()
+
+
+@pytest.fixture
+def assert_raises_match() -> str:
+    if sys.version_info >= (3, 11):
+        return "Value should either be valid"
+    else:
+        return ""
+
+
+def test_set_multi_channel_instrument_parameter(
+    dummy_channel_instrument: DummyChannelInstrument, assert_raises_match: str
+):
+    """Tests :class:`MultiChannelInstrumentParameter` set method."""
+    for name, param in dummy_channel_instrument.channels[0].parameters.items():
+        if not param.settable:
+            continue
+
+        channel_parameter = getattr(dummy_channel_instrument.channels, name)
+
+        getval = channel_parameter.get()
+
+        channel_parameter.set(getval[0])
+
+        # Assert channel parameter setters accept what the getter returns (PR #6073)
+        channel_parameter.set(getval)
+
+        with pytest.raises(TypeError, match=assert_raises_match):
+            channel_parameter.set(getval[:-1])
+
+        with pytest.raises(TypeError, match=assert_raises_match):
+            channel_parameter.set(getval + (getval[-1],))
+
+        with pytest.raises(TypeError):
+            channel_parameter.set(object())