initial impl of px.timeline

packages/python/plotly/plotly/express/__init__.py

@@ -28,6 +28,7 @@
     line_geo,
     area,
     bar,
+    timeline,
     bar_polar,
     violin,
     box,
@@ -81,6 +82,7 @@
     "parallel_categories",
     "area",
     "bar",
+    "timeline",
     "bar_polar",
     "violin",
     "box",

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

@@ -358,6 +358,53 @@ def bar(
 bar.__doc__ = make_docstring(bar, append_dict=_cartesian_append_dict)
 
 
+def timeline(
+    data_frame=None,
+    x_start=None,
+    x_end=None,
+    y=None,
+    color=None,
+    facet_row=None,
+    facet_col=None,
+    facet_col_wrap=0,
+    facet_row_spacing=None,
+    facet_col_spacing=None,
+    hover_name=None,
+    hover_data=None,
+    custom_data=None,
+    text=None,
+    animation_frame=None,
+    animation_group=None,
+    category_orders={},
+    labels={},
+    color_discrete_sequence=None,
+    color_discrete_map={},
+    color_continuous_scale=None,
+    range_color=None,
+    color_continuous_midpoint=None,
+    opacity=None,
+    range_x=None,
+    range_y=None,
+    title=None,
+    template=None,
+    width=None,
+    height=None,
+):
+    """
+    In a timeline plot, each row of `data_frame` is represented as a rectangular
+    mark on an x axis of type `date`, spanning from `x_start` to `x_end`.
+    """
+    return make_figure(
+        args=locals(),
+        constructor="timeline",
+        trace_patch=dict(textposition="auto", orientation="h"),
+        layout_patch=dict(barmode="overlay"),
+    )
+
+
+timeline.__doc__ = make_docstring(timeline)
+
+
 def histogram(
     data_frame=None,
     x=None,

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

@@ -19,7 +19,7 @@
 
 # Declare all supported attributes, across all plot types
 direct_attrables = (
-    ["x", "y", "z", "a", "b", "c", "r", "theta", "size", "base"]
+    ["base", "x", "y", "z", "a", "b", "c", "r", "theta", "size", "x_start", "x_end"]
     + ["hover_name", "text", "names", "values", "parents", "wide_cross"]
     + ["ids", "error_x", "error_x_minus", "error_y", "error_y_minus", "error_z"]
     + ["error_z_minus", "lat", "lon", "locations", "animation_group"]
@@ -610,7 +610,8 @@ def configure_cartesian_axes(args, fig, orders):
     # Set x-axis titles and axis options in the bottom-most row
     x_title = get_decorated_label(args, args["x"], "x")
     for xaxis in fig.select_xaxes(row=1):
-        xaxis.update(title_text=x_title)
+        if "is_timeline" not in args:
+            xaxis.update(title_text=x_title)
         set_cartesian_axis_opts(args, xaxis, "x", orders)
 
     # Configure axis type across all x-axes
@@ -621,6 +622,9 @@ def configure_cartesian_axes(args, fig, orders):
     if "log_y" in args and args["log_y"]:
         fig.update_yaxes(type="log")
 
+    if "is_timeline" in args:
+        fig.update_xaxes(type="date")
+
     return fig.layout
 
 
@@ -1354,6 +1358,7 @@ def build_dataframe(args, constructor):
     if type(args.get("color", None)) == str and args["color"] == NO_COLOR:
         no_color = True
         args["color"] = None
+
     # now that things have been prepped, we do the systematic rewriting of `args`
 
     df_output, wide_id_vars = process_args_into_dataframe(
@@ -1599,6 +1604,30 @@ def aggfunc_continuous(x):
     return args
 
 
+def process_dataframe_timeline(args):
+    """
+    Massage input for bar traces for px.timeline()
+    """
+    args["is_timeline"] = True
+    if args["x_start"] is None or args["x_end"] is None:
+        raise ValueError("Both x_start and x_end are required")
+
+    try:
+        x_start = pd.to_datetime(args["data_frame"][args["x_start"]])
+        x_end = pd.to_datetime(args["data_frame"][args["x_end"]])
+    except TypeError:
+        raise TypeError(
+            "Both x_start and x_end must refer to data convertible to datetimes."
+        )
+
+    # note that we are not adding any columns to the data frame here, so no risk of overwrite
+    args["data_frame"][args["x_end"]] = (x_end - x_start).astype("timedelta64[ms]")
+    args["x"] = args["x_end"]
+    del args["x_end"]
+    args["base"] = args["x_start"]
+    del args["x_start"]
+
+
 def infer_config(args, constructor, trace_patch, layout_patch):
     attrs = [k for k in direct_attrables + array_attrables if k in args]
     grouped_attrs = []
@@ -1801,6 +1830,9 @@ def make_figure(args, constructor, trace_patch=None, layout_patch=None):
     args = build_dataframe(args, constructor)
     if constructor in [go.Treemap, go.Sunburst] and args["path"] is not None:
         args = process_dataframe_hierarchy(args)
+    if constructor == "timeline":
+        constructor = go.Bar
+        args = process_dataframe_timeline(args)
 
     trace_specs, grouped_mappings, sizeref, show_colorbar = infer_config(
         args, constructor, trace_patch, layout_patch

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

@@ -36,6 +36,16 @@
         colref_desc,
         "Values from this column or array_like are used to position marks along the z axis in cartesian coordinates.",
     ],
+    x_start=[
+        colref_type,
+        colref_desc,
+        "Values from this column or array_like are used to position marks along the x axis in cartesian coordinates.",
+    ],
+    x_end=[
+        colref_type,
+        colref_desc,
+        "Values from this column or array_like are used to position marks along the x axis in cartesian coordinates.",
+    ],
     a=[
         colref_type,
         colref_desc,