Merge branch 'copilot/implement-waterfall-graph-function' of https://github.com/sdpython/teachpyx into copilot/implement-waterfall-graph-function

Author: xadupre

_doc/api/tools/pandas.rst

@@ -2,6 +2,24 @@
 teachpyx.tools.pandas
 =====================
 
+Example
+-------
+
+.. plot::
+
+    import pandas
+    import matplotlib.pyplot as plt
+    from teachpyx.tools.pandas import plot_waterfall
+
+    plt.close("all")
+
+    df = pandas.DataFrame({"name": ["A", "B", "C"], "delta": [10, -3, 5]})
+    ax, _ = plot_waterfall(df, "delta", "name", total_label="TOTAL")
+    ax.set_title("Example waterfall")
+    plt.xticks(rotation=30, ha="right")
+    plt.tight_layout()
+    plt.show()
+
 .. automodule:: teachpyx.tools.pandas
     :members:
     :no-undoc-members:

teachpyx/tools/pandas.py

@@ -77,12 +77,7 @@ def plot_waterfall(
     if len(colors) != 3:
         raise ValueError(f"colors must contain 3 values, not {len(colors)}.")
 
-    try:
-        values = pandas.to_numeric(data[value_column], errors="raise").astype(float)
-    except ValueError as exc:
-        raise ValueError(
-            f"Column {value_column!r} cannot be converted to numeric values."
-        ) from exc
+    values = pandas.to_numeric(data[value_column], errors="raise").astype(float)
     labels = data[label_column] if label_column is not None else data.index
     labels = labels.astype(str)