bug fix #16524

doc/source/whatsnew/v0.20.2.txt

@@ -54,6 +54,7 @@ Conversion
 
 - Bug in ``pd.to_numeric()`` in which empty data inputs were causing Python to crash (:issue:`16302`)
 - Silence numpy warnings when broadcasting DataFrame to Series with comparison ops (:issue:`16378`, :issue:`16306`)
+- Bug in ``Series`` with dtype='category' (:issue:`16524`)
 
 
 Indexing

pandas/core/categorical.py

@@ -248,7 +248,8 @@ class Categorical(PandasObject):
     __array_priority__ = 1000
     _typ = 'categorical'
 
-    def __init__(self, values, categories=None, ordered=False, fastpath=False):
+    def __init__(self, values, categories=None, ordered=False, fastpath=False,
+                 **kwargs):
 
         self._validate_ordered(ordered)
 

pandas/tests/series/test_dtypes.py

@@ -12,7 +12,8 @@
 from numpy import nan
 import numpy as np
 
-from pandas import Series, Timestamp, Timedelta, DataFrame, date_range
+from pandas import (Categorical, Series, Timestamp, Timedelta,
+                    DataFrame, date_range)
 
 from pandas.compat import lrange, range, u
 from pandas import compat
@@ -248,3 +249,11 @@ def test_intercept_astype_object(self):
 
         result = df.values.squeeze()
         assert (result[:, 0] == expected.values).all()
+
+    def test_series_to_categorical(self):
+        series = Series(['a', 'b', 'c'])
+
+        categorical_series = Series(series, dtype='category')
+        expected = Series(['a', 'b', 'c'], dtype='category')
+
+        tm.assert_series_equal(categorical_series, expected)