fix bug with pandas categorical series (#72)

CHANGELOG.md

@@ -10,6 +10,12 @@
 
 ### Deprecation
 
+### v0.3.2
+
+### Maintenance and fixes
+
+- Fixed a bug in `CategoricalBox` because it failed to convert categorical series to numpy arrays. Now it works. (#72)
+
 ### v0.3.1
 
 ### Maintenance and fixes

formulae/categorical.py

@@ -87,7 +87,7 @@ def data(self):
     @data.setter
     def data(self, value):
         if isinstance(value, pd.Series):
-            value = value.values
+            value = np.asarray(value)
         if not (isinstance(value, np.ndarray) and value.ndim == 1):  # pragma: no cover
             raise ValueError("The data argument must be one dimensional array-like")
         self._data = value

formulae/tests/test_design_matrices.py

@@ -1131,3 +1131,9 @@ def test_extra_namespace(data):
     )
     df = dm.common.as_dataframe()
     assert df["myfunc(x3)"].equals(np.log(df["x3"]))
+
+
+def test_categorical_series():
+    data = pd.DataFrame({"x": list("abc") * 10})
+    data["x"] = pd.Categorical(data["x"], list("abc"), ordered=True)
+    design_matrices("S(x)", data)

formulae/version.py

@@ -1 +1 @@
-__version__ = "0.3.1"
+__version__ = "0.3.2"