Add support for pandas 2.1

holonote/annotate/table.py

@@ -216,7 +216,10 @@ def _add_annotation_fields(self, index_value, fields=None):
 
         new_fields = pd.DataFrame([dict(fields, **{self._field_df.index.name:index_value})])
         new_fields = new_fields.set_index(self._field_df.index.name)
-        self._field_df =   pd.concat((self._field_df, new_fields))
+        if self._field_df.empty:
+            self._field_df = new_fields
+        else:
+            self._field_df = pd.concat((self._field_df, new_fields))
 
     def delete_annotation(self, index):
         if index is None:

pyproject.toml

@@ -16,7 +16,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Operating System :: OS Independent",
 ]
-dependencies = ["holoviews", "pandas <2.1"]
+dependencies = ["holoviews", "pandas"]
 
 [tool.hatch.version]
 source = "vcs"
@@ -35,11 +35,13 @@ scripts.update = "pre-commit autoupdate"
 addopts = "-vv"
 filterwarnings = [
     "error",
-    # 2023-09: Ignore Bokeh UserWarning, which needs to be fixed in HoloViews
+    # 2023-09: Ignore Bokeh UserWarning, will be fixed in HoloViews 1.18
     "ignore:found multiple competing values for:UserWarning:holoviews.plotting.bokeh.plot",
     # 2023-09: Wrong warning, when a timedelta is compared to another scalar.
     # Fixed in newer versions of Numpy: https://github.com/numpy/numpy/issues/10095
     "ignore:elementwise comparison failed:DeprecationWarning:bokeh.core.property.bases",
+    # 2023-09: Ignore Pandas FutureWarning, will be fixed in HoloViews 1.18
+    "ignore:Series.__getitem__ treating keys:FutureWarning:holoviews.core.data.pandas",
 ]
 
 [tool.ruff]