Update is_categorical_dtype for pandas>=2.1.0 (#105)

formulae/terms/call.py

@@ -4,12 +4,13 @@
 import numpy as np
 import pandas as pd
 
-from pandas.api.types import is_categorical_dtype, is_numeric_dtype, is_string_dtype
+from pandas.api.types import is_numeric_dtype, is_string_dtype
 
 from formulae.categorical import ENCODINGS, CategoricalBox, Treatment
 from formulae.config import config
 from formulae.transforms import TRANSFORMS, Proportion, Offset
 from formulae.terms.call_utils import CallVarsExtractor
+from formulae.utils import is_categorical_dtype
 
 
 class Call:

formulae/terms/variable.py

@@ -4,10 +4,11 @@
 import numpy as np
 import pandas as pd
 
-from pandas.api.types import is_categorical_dtype, is_numeric_dtype, is_string_dtype
+from pandas.api.types import is_numeric_dtype, is_string_dtype
 
 from formulae.config import config
 from formulae.categorical import Treatment
+from formulae.utils import is_categorical_dtype
 
 
 class Variable:

formulae/utils.py

@@ -1,6 +1,7 @@
 from copy import deepcopy
 
 import numpy as np
+import pandas as pd
 
 
 def listify(obj):
@@ -38,3 +39,16 @@ def get_interaction_matrix(x, y):
  for j2 in range(y.shape[1]):
  l.append(x[:, j1] * y[:, j2])
  return np.column_stack(l)
+
+
+def is_categorical_dtype(arr_or_dtype):
+ """Check whether an array-like or dtype is of the pandas Categorical dtype."""
+ # https://pandas.pydata.org/docs/whatsnew/v2.1.0.html#other-deprecations
+ if pd.__version__ < "2.1.0":
+ return pd.api.types.is_categorical_dtype(arr_or_dtype)
+ else:
+ if hasattr(arr_or_dtype, "dtype"): # it's an array
+ dtype = getattr(arr_or_dtype, "dtype")
+ else:
+ dtype = arr_or_dtype
+ return isinstance(dtype, pd.CategoricalDtype)