ability to show markers on lines

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

@@ -212,6 +212,7 @@ def line(
     line_group=None,
     color=None,
     line_dash=None,
+    symbol=None,
     hover_name=None,
     hover_data=None,
     custom_data=None,
@@ -234,6 +235,9 @@ def line(
     color_discrete_map=None,
     line_dash_sequence=None,
     line_dash_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     log_x=False,
     log_y=False,
     range_x=None,
@@ -261,6 +265,7 @@ def area(
     y=None,
     line_group=None,
     color=None,
+    symbol=None,
     hover_name=None,
     hover_data=None,
     custom_data=None,
@@ -276,6 +281,9 @@ def area(
     labels=None,
     color_discrete_sequence=None,
     color_discrete_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     orientation=None,
     groupnorm=None,
     log_x=False,
@@ -692,6 +700,7 @@ def line_3d(
     line_dash=None,
     text=None,
     line_group=None,
+    symbol=None,
     hover_name=None,
     hover_data=None,
     custom_data=None,
@@ -709,6 +718,9 @@ def line_3d(
     color_discrete_map=None,
     line_dash_sequence=None,
     line_dash_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     log_x=False,
     log_y=False,
     log_z=False,
@@ -778,6 +790,7 @@ def line_ternary(
     color=None,
     line_dash=None,
     line_group=None,
+    symbol=None,
     hover_name=None,
     hover_data=None,
     custom_data=None,
@@ -790,6 +803,9 @@ def line_ternary(
     color_discrete_map=None,
     line_dash_sequence=None,
     line_dash_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     line_shape=None,
     title=None,
     template=None,
@@ -862,6 +878,7 @@ def line_polar(
     custom_data=None,
     line_group=None,
     text=None,
+    symbol=None,
     animation_frame=None,
     animation_group=None,
     category_orders=None,
@@ -870,6 +887,9 @@ def line_polar(
     color_discrete_map=None,
     line_dash_sequence=None,
     line_dash_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     direction="clockwise",
     start_angle=90,
     line_close=False,
@@ -1067,6 +1087,7 @@ def line_geo(
     hover_data=None,
     custom_data=None,
     line_group=None,
+    symbol=None,
     animation_frame=None,
     animation_group=None,
     category_orders=None,
@@ -1075,6 +1096,9 @@ def line_geo(
     color_discrete_map=None,
     line_dash_sequence=None,
     line_dash_map=None,
+    symbol_sequence=None,
+    symbol_map=None,
+    markers=False,
     projection=None,
     scope=None,
     center=None,

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

@@ -1782,8 +1782,13 @@ def infer_config(args, constructor, trace_patch, layout_patch):
             trace_patch["opacity"] = args["opacity"]
         else:
             trace_patch["marker"] = dict(opacity=args["opacity"])
-    if "line_group" in args:
-        trace_patch["mode"] = "lines" + ("+markers+text" if args["text"] else "")
+    if "line_group" in args:  # px.line, px.line_*, px.area
+        modes = set(["lines"])
+        if args.get("text") or args.get("symbol") or args.get("markers"):
+            modes.add("markers")
+        if args.get("text"):
+            modes.add("text")
+        trace_patch["mode"] = "+".join(modes)
     elif constructor != go.Splom and (
         "symbol" in args or constructor == go.Scattermapbox
     ):

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

@@ -325,6 +325,7 @@
         "Setting this value is recommended when using `plotly.express.colors.diverging` color scales as the inputs to `color_continuous_scale`.",
     ],
     size_max=["int (default `20`)", "Set the maximum mark size when using `size`."],
+    markers=["boolean (default `False`)", "If `True`, markers are shown on lines.",],
     log_x=[
         "boolean (default `False`)",
         "If `True`, the x-axis is log-scaled in cartesian coordinates.",