Add a converter for dt.timedelta.

Signed-off-by: Michael Johansen <[email protected]>

Author: Michael Johansen

examples/all_types/define_types.py

@@ -72,6 +72,7 @@ class MyMixedEnum(enum.Enum):
     "int": 42,
     "str": "sample string",
     "dt_datetime": dt.datetime.now(),
+    "dt_timedelta": dt.timedelta(weeks=2, days=5, minutes=12, milliseconds=75),
     # supported enum and flag types
     "intflags": MyIntFlags.VALUE1 | MyIntFlags.VALUE4,
     "intenum": MyIntEnum.VALUE20,

src/nipanel/_convert.py

@@ -13,6 +13,7 @@
     BoolConverter,
     BytesConverter,
     DTDateTimeConverter,
+    DTTimeDeltaConverter,
     FloatConverter,
     IntConverter,
     StrConverter,
@@ -39,6 +40,7 @@
     IntConverter(),
     StrConverter(),
     DTDateTimeConverter(),
+    DTTimeDeltaConverter(),
     # Containers next
     BoolCollectionConverter(),
     BytesCollectionConverter(),

src/nipanel/converters/builtin.py

@@ -4,7 +4,7 @@
 from collections.abc import Collection
 from typing import Type
 
-from google.protobuf import timestamp_pb2, wrappers_pb2
+from google.protobuf import duration_pb2, timestamp_pb2, wrappers_pb2
 from ni.panels.v1 import panel_types_pb2
 
 from nipanel.converters import Converter
@@ -144,6 +144,30 @@ def to_python_value(self, protobuf_message: timestamp_pb2.Timestamp) -> dt.datet
         return protobuf_message.ToDatetime()
 
 
+class DTTimeDeltaConverter(Converter[dt.timedelta, duration_pb2.Duration]):
+    """A converter for datetime.timedelta types."""
+
+    @property
+    def python_typename(self) -> str:
+        """The Python type that this converter handles."""
+        return dt.timedelta.__name__
+
+    @property
+    def protobuf_message(self) -> Type[duration_pb2.Duration]:
+        """The type-specific protobuf message for the Python type."""
+        return duration_pb2.Duration
+
+    def to_protobuf_message(self, python_value: dt.timedelta) -> duration_pb2.Duration:
+        """Convert the Python dt.timedelta to a protobuf duration_pb2.Duration."""
+        dur = self.protobuf_message()
+        dur.FromTimedelta(python_value)
+        return dur
+
+    def to_python_value(self, protobuf_message: duration_pb2.Duration) -> dt.timedelta:
+        """Convert the protobuf timestamp_pb2.Timestamp to a Python dt.timedelta."""
+        return protobuf_message.ToTimedelta()
+
+
 class BoolCollectionConverter(Converter[Collection[bool], panel_types_pb2.BoolCollection]):
     """A converter for a Collection of bools."""
 

tests/unit/test_convert.py

@@ -3,7 +3,7 @@
 
 import numpy as np
 import pytest
-from google.protobuf import any_pb2, timestamp_pb2, wrappers_pb2
+from google.protobuf import any_pb2, duration_pb2, timestamp_pb2, wrappers_pb2
 from google.protobuf.message import Message
 from ni.panels.v1 import panel_types_pb2
 from ni.protobuf.types.scalar_pb2 import ScalarData
@@ -135,6 +135,16 @@ def test___python_datetime_datetime___to_any___valid_timestamppb2_value() -> Non
     assert unpack_dest.ToDatetime() == expected_value
 
 
+def test___python_datetime_timedelta___to_any___valid_durationpb2_value() -> None:
+    expected_value = dt.timedelta(days=1, seconds=1, microseconds=1)
+    result = nipanel._convert.to_any(expected_value)
+    unpack_dest = duration_pb2.Duration()
+    _assert_any_and_unpack(result, unpack_dest)
+
+    assert isinstance(unpack_dest, duration_pb2.Duration)
+    assert unpack_dest.ToTimedelta() == expected_value
+
+
 @pytest.mark.parametrize(
     "proto_type, default_value, expected_value",
     [
@@ -199,6 +209,18 @@ def test___timestamppb2_timestamp___from_any___valid_python_value() -> None:
     assert result == expected_value
 
 
+def test___durationpb2_timestamp___from_any___valid_python_value() -> None:
+    expected_value = dt.timedelta(weeks=1, hours=1, minutes=1)
+    pb_value = duration_pb2.Duration()
+    pb_value.FromTimedelta(expected_value)
+    packed_any = _pack_into_any(pb_value)
+
+    result = nipanel._convert.from_any(packed_any)
+
+    assert isinstance(result, dt.timedelta)
+    assert result == expected_value
+
+
 @pytest.mark.parametrize(
     "proto_type, expected_value",
     [