Add unit to view instrument selection criteria

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 - Use BoundedAttributes instead of raw dict to extract attributes from LogRecord and Support dropped_attributes_count in LogRecord ([#3310](https://github.com/open-telemetry/opentelemetry-python/pull/3310))
+- Add unit to view instrument selection criteria
+  ([#3341](https://github.com/open-telemetry/opentelemetry-python/pull/3341))
+
 ## Version 1.18.0/0.39b0 (2023-05-04)
 
 - Select histogram aggregation with an environment variable

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/view.py

@@ -51,6 +51,9 @@ class View:
             card characters should not be used with this attribute if the view has also a
             ``name`` defined.
 
+        instrument_unit: This is an instrument matching attribute: the unit the
+            instrument must have to match the view.
+
         meter_name: This is an instrument matching attribute: the name the
             instrument meter must have to match the view.
 
@@ -85,6 +88,7 @@ def __init__(
         self,
         instrument_type: Optional[Type[Instrument]] = None,
         instrument_name: Optional[str] = None,
+        instrument_unit: Optional[str] = None,
         meter_name: Optional[str] = None,
         meter_version: Optional[str] = None,
         meter_schema_url: Optional[str] = None,
@@ -96,6 +100,7 @@ def __init__(
         if (
             instrument_type
             is instrument_name
+            is instrument_unit
             is meter_name
             is meter_version
             is meter_schema_url
@@ -122,6 +127,7 @@ def __init__(
         self._name = name
         self._instrument_type = instrument_type
         self._instrument_name = instrument_name
+        self._instrument_unit = instrument_unit
         self._meter_name = meter_name
         self._meter_version = meter_version
         self._meter_schema_url = meter_schema_url
@@ -143,6 +149,10 @@ def _match(self, instrument: Instrument) -> bool:
             if not fnmatch(instrument.name, self._instrument_name):
                 return False
 
+        if self._instrument_unit is not None:
+            if not fnmatch(instrument.unit, self._instrument_unit):
+                return False
+
         if self._meter_name is not None:
             if instrument.instrumentation_scope.name != self._meter_name:
                 return False

opentelemetry-sdk/tests/metrics/test_view.py

@@ -37,6 +37,15 @@ def test_instrument_name(self):
             View(instrument_name="instrument_name")._match(mock_instrument)
         )
 
+    def test_instrument_unit(self):
+
+        mock_instrument = Mock()
+        mock_instrument.configure_mock(**{"unit": "instrument_unit"})
+
+        self.assertTrue(
+            View(instrument_unit="instrument_unit")._match(mock_instrument)
+        )
+
     def test_meter_name(self):
 
         self.assertTrue(