Simplify ScenarioInfo.yv_ya using DataFrame.query()

message_ix_models/util/scenarioinfo.py

@@ -132,22 +132,13 @@ def from_url(cls, url: str) -> "ScenarioInfo":
     def yv_ya(self):
         """:class:`pandas.DataFrame` with valid ``year_vtg``, ``year_act`` pairs."""
         if self._yv_ya is None:
-            first = self.y0
-
-            # Product of all years
-            yv = ya = self.set["year"]
-
-            # Predicate for filtering years
-            def _valid(elem):
-                yv, ya = elem
-                return first <= yv <= ya
-
             # - Cartesian product of all yv and ya.
-            # - Filter only valid years.
             # - Convert to data frame.
+            # - Filter only valid years.
             self._yv_ya = pd.DataFrame(
-                filter(_valid, product(yv, ya)), columns=["year_vtg", "year_act"]
-            )
+                product(self.set["year"], self.set["year"]),
+                columns=["year_vtg", "year_act"],
+            ).query("@self.y0 <= year_vtg <= year_act")
 
         return self._yv_ya