Add Dataset.tables_rows

audbcards/core/dataset.py

@@ -541,12 +541,7 @@ def tables_preview(self) -> typing.Dict[str, typing.List[typing.List[str]]]:
         """
         preview = {}
         for table in list(self.header):
-            df = audb.load_table(
-                self.name,
-                table,
-                version=self.version,
-                verbose=False,
-            )
+            df = self._tables[table]
             df = df.reset_index()
             header = [df.columns.tolist()]
             body = df.head(5).astype("string").values.tolist()
@@ -555,6 +550,26 @@ def tables_preview(self) -> typing.Dict[str, typing.List[typing.List[str]]]:
             preview[table] = header + body
         return preview
 
+    @functools.cached_property
+    def tables_rows(self) -> typing.Dict[str, int]:
+        """Number of rows for each table of the dataset.
+
+        Returns:
+            dictionary with table IDs as keys
+            and number of rows as values
+
+        Examples:
+            >>> ds = Dataset("emodb", "1.4.1")
+            >>> ds.tables_rows["speaker"]
+            10
+
+        """
+        rows = {}
+        for table in list(self.header):
+            df = self._tables[table]
+            rows[table] = len(df)
+        return rows
+
     @functools.cached_property
     def tables_table(self) -> typing.List[str]:
         """Tables of the dataset."""
@@ -751,6 +766,20 @@ def _segments(self) -> pd.MultiIndex:
                 index = audformat.utils.union([index, df.index])
         return index
 
+    @functools.cached_property
+    def _tables(self) -> typing.Dict[str, pd.DataFrame]:
+        """Dataframes of tables in the dataset."""
+        tables = {}
+        for table in list(self.header):
+            df = audb.load_table(
+                self.name,
+                table,
+                version=self.version,
+                verbose=False,
+            )
+            tables[table] = df
+        return tables
+
     @staticmethod
     def _map_iso_languages(languages: typing.List[str]) -> typing.List[str]:
         r"""Calculate ISO languages for a list of languages.

audbcards/core/templates/datacard_tables.j2

@@ -44,6 +44,7 @@ Tables
     </tr>
     {% endif %}
     {% endfor %}
+    <tr><td><p>{{ tables_rows[row[0]] }} rows</p></td></tr>
     </tbody>
     </table>
 

tests/test_dataset.py

@@ -205,6 +205,12 @@ def test_dataset(audb_cache, tmpdir, repository, db, request):
     expected_tables = list(db)
     assert dataset.tables == expected_tables
 
+    # tables_rows
+    expected_tables_rows = {}
+    for table_id in list(db):
+        expected_tables_rows[table_id] = len(db[table_id])
+    assert dataset.tables_rows == expected_tables_rows
+
     # tables_table
     expected_tables_table = [["ID", "Type", "Columns"]]
     for table_id in list(db):