Add subtitle attribute to Plotly Express figures

CHANGELOG.md

@@ -9,6 +9,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Updated
 
 - Updated plotly.py to use base64 encoding of arrays in plotly JSON to improve performance. 
+- Add `subtitle` attribute to all Plotly Express traces
 
 ## [5.24.1] - 2024-09-12
 

packages/python/plotly/plotly/express/_chart_types.py

@@ -55,6 +55,7 @@ def scatter(
     range_y=None,
     render_mode="auto",
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -105,6 +106,7 @@ def density_contour(
     nbinsy=None,
     text_auto=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -175,6 +177,7 @@ def density_heatmap(
     nbinsy=None,
     text_auto=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -253,6 +256,7 @@ def line(
     line_shape=None,
     render_mode="auto",
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -303,6 +307,7 @@ def area(
     range_y=None,
     line_shape=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -362,6 +367,7 @@ def bar(
     range_y=None,
     text_auto=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -412,6 +418,7 @@ def timeline(
     range_x=None,
     range_y=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -467,6 +474,7 @@ def histogram(
     nbins=None,
     text_auto=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -541,6 +549,7 @@ def ecdf(
     range_x=None,
     range_y=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -597,6 +606,7 @@ def violin(
     points=None,
     box=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -650,6 +660,7 @@ def box(
     points=None,
     notched=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -700,6 +711,7 @@ def strip(
     range_x=None,
     range_y=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -765,6 +777,7 @@ def scatter_3d(
     range_y=None,
     range_z=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -816,6 +829,7 @@ def line_3d(
     range_y=None,
     range_z=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -856,6 +870,7 @@ def scatter_ternary(
     opacity=None,
     size_max=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -896,6 +911,7 @@ def line_ternary(
     markers=False,
     line_shape=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -941,6 +957,7 @@ def scatter_polar(
     log_r=False,
     render_mode="auto",
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -987,6 +1004,7 @@ def line_polar(
     range_theta=None,
     log_r=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1030,6 +1048,7 @@ def bar_polar(
     range_theta=None,
     log_r=False,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1080,6 +1099,7 @@ def choropleth(
     fitbounds=None,
     basemap_visible=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1137,6 +1157,7 @@ def scatter_geo(
     fitbounds=None,
     basemap_visible=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1193,6 +1214,7 @@ def line_geo(
     fitbounds=None,
     basemap_visible=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1236,6 +1258,7 @@ def scatter_map(
     center=None,
     map_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1273,6 +1296,7 @@ def choropleth_map(
     center=None,
     map_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1308,6 +1332,7 @@ def density_map(
     map_style=None,
     radius=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1344,6 +1369,7 @@ def line_map(
     center=None,
     map_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1383,6 +1409,7 @@ def scatter_mapbox(
     center=None,
     mapbox_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1420,6 +1447,7 @@ def choropleth_mapbox(
     center=None,
     mapbox_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1455,6 +1483,7 @@ def density_mapbox(
     mapbox_style=None,
     radius=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1491,6 +1520,7 @@ def line_mapbox(
     center=None,
     mapbox_style=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1526,6 +1556,7 @@ def scatter_matrix(
     opacity=None,
     size_max=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1553,6 +1584,7 @@ def parallel_coordinates(
     range_color=None,
     color_continuous_midpoint=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1577,6 +1609,7 @@ def parallel_categories(
     range_color=None,
     color_continuous_midpoint=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1612,6 +1645,7 @@ def pie(
     category_orders=None,
     labels=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1664,6 +1698,7 @@ def sunburst(
     custom_data=None,
     labels=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1714,6 +1749,7 @@ def treemap(
     custom_data=None,
     labels=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1764,6 +1800,7 @@ def icicle(
     custom_data=None,
     labels=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1823,6 +1860,7 @@ def funnel(
     range_x=None,
     range_y=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,
@@ -1849,6 +1887,7 @@ def funnel_area(
     custom_data=None,
     labels=None,
     title=None,
+    subtitle=None,
     template=None,
     width=None,
     height=None,

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

@@ -2340,6 +2340,8 @@ def make_figure(args, constructor, trace_patch=None, layout_patch=None):
         layout_patch["title_text"] = args["title"]
     elif args["template"].layout.margin.t is None:
         layout_patch["margin"] = {"t": 60}
+    if args["subtitle"]:
+        layout_patch["title_subtitle_text"] = args["subtitle"]
     if (
         "size" in args
         and args["size"]

packages/python/plotly/plotly/express/_doc.py

@@ -371,6 +371,7 @@
         "If provided, overrides auto-scaling on the angular axis in polar coordinates.",
     ],
     title=["str", "The figure title."],
+    subtitle=["str", "The figure subtitle."],
     template=[
         "str or dict or plotly.graph_objects.layout.Template instance",
         "The figure template name (must be a key in plotly.io.templates) or definition.",