add a ranking plugin, which ranks rows.

Author: nickzoic

countess/plugins/ranking.py

@@ -0,0 +1,40 @@
+import logging
+from typing import Optional, Iterable
+
+from countess import VERSION
+from countess.core.parameters import (
+    ArrayParam,
+    ColumnChoiceParam,
+    NumericColumnChoiceParam,
+)
+from countess.core.plugins import DuckdbSqlPlugin
+from countess.utils.duckdb import duckdb_escape_identifier
+
+logger = logging.getLogger(__name__)
+
+
+class RankingPlugin(DuckdbSqlPlugin):
+    name = "Ranking"
+    description = "Rank rows by column value(s)"
+    version = VERSION
+
+    order_by = ArrayParam("Order By", NumericColumnChoiceParam("Column"))
+    partition = ArrayParam("Partition By", ColumnChoiceParam("Column"))
+
+    def sql(self, table_name: str, columns: Iterable[str]) -> Optional[str]:
+
+        order_by = ', '.join(
+            duckdb_escape_identifier(p.value)
+            for p in self.order_by.params
+        )
+        if order_by:
+            order_by = f"ORDER BY {order_by}"
+
+        partition = ', '.join(
+            duckdb_escape_identifier(p.value)
+            for p in self.partition.params
+        )
+        if partition:
+            partition = f"PARTITION BY {partition}"
+
+        return f'SELECT *, percent_rank({order_by}) over ({partition}) as rank FROM {table_name}'

pyproject.toml

@@ -75,6 +75,7 @@ variant_classifier = "countess.plugins.variant:VariantClassifier"
 variant_converter = "countess.plugins.variant:VariantConverter"
 frequency = "countess.plugins.frequency:FrequencyPlugin"
 columns = "countess.plugins.columns:ColumnsPlugin"
+ranking = "countess.plugins.ranking:RankingPlugin"
 
 [project.entry-points.gui_scripts]
 countess_gui = "countess.gui.main:main"