corrected color bug in pie/sunburst etc

doc/python/pie-charts.md

@@ -5,7 +5,7 @@ jupyter:
     text_representation:
       extension: .md
       format_name: markdown
-      format_version: "1.2"
+      format_version: '1.2'
       jupytext_version: 1.3.0
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     display_name: Python 3
@@ -73,6 +73,21 @@ fig = px.pie(df, values='tip', names='day', color_discrete_sequence=px.colors.se
 fig.show()
 ```
 
+### Using an explicit mapping for discrete colors
+
+For more information about discrete colors, see the [dedicated page](/python/discrete-color).
+
+```python
+import plotly.express as px
+df = px.data.tips()
+fig = px.pie(df, values='tip', names='day', color='day',
+             color_discrete_map={'Thur':'lightcyan', 
+                                 'Fri':'cyan', 
+                                 'Sat':'royalblue', 
+                                 'Sun':'darkblue'})
+fig.show()
+```
+
 ### Customizing a pie chart created with px.pie
 
 In the example below, we first create a pie chart with `px,pie`, using some of its options such as `hover_data` (which columns should appear in the hover) or `labels` (renaming column names). For further tuning, we call `fig.update_traces` to set other parameters of the chart (you can also use `fig.update_layout` for changing the layout).

doc/python/sunburst-charts.md

@@ -5,7 +5,7 @@ jupyter:
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       extension: .md
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       jupytext_version: 1.3.0
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     display_name: Python 3
@@ -109,6 +109,18 @@ fig = px.sunburst(df, path=['sex', 'day', 'time'], values='total_bill', color='t
 fig.show()
 ```
 
+### Using an explicit mapping for discrete colors
+
+For more information about discrete colors, see the [dedicated page](/python/discrete-color).
+
+```python
+import plotly.express as px
+df = px.data.tips()
+fig = px.sunburst(df, path=['sex', 'day', 'time'], values='total_bill', color='time',
+                  color_discrete_map={'(?)':'black', 'Lunch':'gold', 'Dinner':'darkblue'})
+fig.show()
+```
+
 ### Rectangular data with missing values
 
 If the dataset is not fully rectangular, missing values should be supplied as `None`. Note that the parents of `None` entries must be a leaf, i.e. it cannot have other children than `None` (otherwise a `ValueError` is raised).

doc/python/treemaps.md

@@ -5,8 +5,8 @@ jupyter:
     text_representation:
       extension: .md
       format_name: markdown
-      format_version: "1.2"
-      jupytext_version: 1.3.1
+      format_version: '1.2'
+      jupytext_version: 1.3.0
   kernelspec:
     display_name: Python 3
     language: python
@@ -20,7 +20,7 @@ jupyter:
     name: python
     nbconvert_exporter: python
     pygments_lexer: ipython3
-    version: 3.6.8
+    version: 3.7.3
   plotly:
     description: How to make Treemap Charts with Plotly
     display_as: basic
@@ -101,6 +101,18 @@ fig = px.treemap(df, path=['all', 'sex', 'day', 'time'], values='total_bill', co
 fig.show()
 ```
 
+### Using an explicit mapping for discrete colors
+
+For more information about discrete colors, see the [dedicated page](/python/discrete-color).
+
+```python
+import plotly.express as px
+df = px.data.tips()
+fig = px.treemap(df, path=['sex', 'day', 'time'], values='total_bill', color='time',
+                  color_discrete_map={'(?)':'black', 'Lunch':'gold', 'Dinner':'darkblue'})
+fig.show()
+```
+
 ### Rectangular data with missing values
 
 If the dataset is not fully rectangular, missing values should be supplied as `None`.

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

@@ -331,7 +331,10 @@ def make_trace_kwargs(args, trace_spec, trace_data, mapping_labels, sizeref):
                         mapping_labels[attr_label] = "%{color}"
                     else:
                         trace_patch["marker"]["colors"] = []
-                        mapping = {}
+                        if args["color_discrete_map"] is not None:
+                            mapping = args["color_discrete_map"].copy()
+                        else:
+                            mapping = {}
                         for cat in trace_data[attr_value]:
                             if mapping.get(cat) is None:
                                 mapping[cat] = args["color_discrete_sequence"][

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

@@ -218,6 +218,11 @@ def test_sunburst_treemap_with_path_color():
     fig = px.sunburst(df, path=path, color="vendors")
     assert len(np.unique(fig.data[0].marker.colors)) == 9
 
+    # Discrete color and color_discrete_map
+    cmap = {"Tech": "yellow", "Finance": "magenta", "(?)": "black"}
+    fig = px.sunburst(df, path=path, color="sectors", color_discrete_map=cmap)
+    assert np.all(np.in1d(fig.data[0].marker.colors, list(cmap.values())))
+
     # Numerical column in path
     df["regions"] = df["regions"].map({"North": 1, "South": 2})
     path = ["total", "regions", "sectors", "vendors"]