accept integer and float columns in wide mode

CHANGELOG.md

@@ -9,6 +9,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed special cases with `px.sunburst` and `px.treemap` with `path` input ([#2524](https://github.com/plotly/plotly.py/pull/2524))
 - Fixed bug in `hover_data` argument of `px` functions, when the column name is changed with labels and `hover_data` is a dictionary setting up a specific format for the hover data ([#2544](https://github.com/plotly/plotly.py/pull/2544)).
 - Made the Plotly Express `trendline` argument more robust and made it work with datetime `x` values ([#2554](https://github.com/plotly/plotly.py/pull/2554))
+- Plotly Express wide mode now accepts mixed integer and float columns ([#2598](https://github.com/plotly/plotly.py/pull/2598))
 
 ## [4.8.1] - 2020-05-28
 

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

@@ -1390,9 +1390,11 @@ def build_dataframe(args, constructor):
         del args["wide_cross"]
         dtype = None
         for v in wide_value_vars:
+            v_dtype = df_output[v].dtype.kind
+            v_dtype = "number" if v_dtype in ["i", "f", "u"] else v_dtype
             if dtype is None:
-                dtype = df_output[v].dtype
-            elif dtype != df_output[v].dtype:
+                dtype = v_dtype
+            elif dtype != v_dtype:
                 raise ValueError(
                     "Plotly Express cannot process wide-form data with columns of different type."
                 )

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

@@ -742,3 +742,9 @@ def test_mixed_input_error(df):
         "Plotly Express cannot process wide-form data with columns of different type"
         in str(err_msg.value)
     )
+
+
+def test_mixed_number_input():
+    df = pd.DataFrame(dict(a=[1, 2], b=[1.1, 2.1]))
+    fig = px.line(df)
+    assert len(fig.data) == 2