tuple possible in hover_data dict

Author: emmanuelle

packages/python/plotly/plotly/express/_core.py

@@ -396,10 +396,10 @@ def make_trace_kwargs(args, trace_spec, trace_data, mapping_labels, sizeref):
         if args["hover_data"] and isinstance(args["hover_data"], dict):
             for k, v in mapping_labels.items():
                 if k in args["hover_data"]:
-                    if args["hover_data"][k]:
-                        if isinstance(args["hover_data"][k], str):
+                    if args["hover_data"][k][0]:
+                        if isinstance(args["hover_data"][k][0], str):
                             mapping_labels_copy[k] = v.replace(
-                                "}", "%s}" % args["hover_data"][k]
+                                "}", "%s}" % args["hover_data"][k][0]
                             )
                     else:
                         _ = mapping_labels_copy.pop(k)
@@ -935,6 +935,17 @@ def build_dataframe(args, attrables, array_attrables):
         else:
             df_output[df_input.columns] = df_input[df_input.columns]
 
+    # hover_data is a dict
+    hover_data_is_dict = (
+        "hover_data" in args
+        and args["hover_data"]
+        and isinstance(args["hover_data"], dict)
+    )
+    if hover_data_is_dict:
+        for k in args["hover_data"]:
+            if not isinstance(args["hover_data"][k], tuple):
+                args["hover_data"][k] = (args["hover_data"][k], None)
+
     # Loop over possible arguments
     for field_name in attrables:
         # Massaging variables
@@ -970,15 +981,20 @@ def build_dataframe(args, attrables, array_attrables):
             if isinstance(argument, str) or isinstance(
                 argument, int
             ):  # just a column name given as str or int
-                if not df_provided:
+                bypass_warnings = (
+                    hover_data_is_dict
+                    and argument in args["hover_data"]
+                    and args["hover_data"][argument][1]
+                )
+                if not df_provided and not bypass_warnings:
                     raise ValueError(
                         "String or int arguments are only possible when a "
                         "DataFrame or an array is provided in the `data_frame` "
                         "argument. No DataFrame was provided, but argument "
                         "'%s' is of type str or int." % field
                     )
                 # Check validity of column name
-                if argument not in df_input.columns:
+                if not bypass_warnings and argument not in df_input.columns:
                     err_msg = (
                         "Value of '%s' is not the name of a column in 'data_frame'. "
                         "Expected one of %s but received: %s"
@@ -989,7 +1005,7 @@ def build_dataframe(args, attrables, array_attrables):
                             "\n To use the index, pass it in directly as `df.index`."
                         )
                     raise ValueError(err_msg)
-                if length and len(df_input[argument]) != length:
+                if not bypass_warnings and length and len(df_input[argument]) != length:
                     raise ValueError(
                         "All arguments should have the same length. "
                         "The length of column argument `df[%s]` is %d, whereas the "
@@ -1002,7 +1018,14 @@ def build_dataframe(args, attrables, array_attrables):
                         )
                     )
                 col_name = str(argument)
-                df_output[col_name] = df_input[argument].values
+                if (
+                    field_name == "hover_data"
+                    and hover_data_is_dict
+                    and args["hover_data"][col_name][1]
+                ):
+                    df_output[col_name] = args["hover_data"][col_name][1]
+                else:
+                    df_output[col_name] = df_input[argument].values
             # ----------------- argument is a column / array / list.... -------
             else:
                 is_index = isinstance(argument, pd.RangeIndex)

packages/python/plotly/plotly/tests/test_core/test_px/test_px_hover.py

@@ -21,7 +21,7 @@ def test_skip_hover():
 def test_composite_hover():
     df = px.data.tips()
     hover_dict = OrderedDict(
-            {"day": False, "sex": True, "time": False, "total_bill": ":.1f"}
+        {"day": False, "sex": True, "time": False, "total_bill": ":.1f"}
     )
     fig = px.scatter(
         df,
@@ -33,5 +33,24 @@ def test_composite_hover():
     )
     assert (
         fig.data[0].hovertemplate
-        == "tip=%{x}<br>total_bill=%{customdata[1]:.1f}<br>sex=%{customdata[0]}<extra></extra>"
+        == "tip=%{x}<br>total_bill=%{customdata[3]:.1f}<br>sex=%{customdata[1]}<extra></extra>"
+    )
+
+
+def test_tuple_hover_data():
+    fig = px.scatter(
+        x=[1, 2, 3], y=[3, 4, 5], hover_data={"comment": (True, ["a", "b", "c"])}
+    )
+    assert (
+        fig.data[0].hovertemplate
+        == "x=%{x}<br>y=%{y}<br>comment=%{customdata[0]}<extra></extra>"
+    )
+    fig = px.scatter(
+        x=[1, 2, 3],
+        y=[3, 4, 5],
+        hover_data={"comment": (":.1f", [1.234, 45.3455, 5666.234])},
+    )
+    assert (
+        fig.data[0].hovertemplate
+        == "x=%{x}<br>y=%{y}<br>comment=%{customdata[0]:.1f}<extra></extra>"
     )