CLN: Removed levels attribute from Categorical

Closes gh-8376.

Author: gfyoung

doc/source/whatsnew/v0.19.0.txt

@@ -467,6 +467,7 @@ Removal of prior version deprecations/changes
 
 - ``DataFrame.to_csv()`` has dropped the ``engine`` parameter, as was deprecated in 0.17.1 (:issue:`11274`, :issue:`13419`)
 - ``DataFrame.to_dict()`` has dropped the ``outtype`` parameter in favor of ``orient`` (:issue:`13627`, :issue:`8486`)
+- ``pd.Categorical`` has dropped the ``levels`` attribute in favour of ``categories`` (:issue:`8376`)
 
 
 .. _whatsnew_0190.performance:

pandas/core/categorical.py

@@ -228,8 +228,8 @@ class Categorical(PandasObject):
     __array_priority__ = 1000
     _typ = 'categorical'
 
-    def __init__(self, values, categories=None, ordered=False, name=None,
-                 fastpath=False, levels=None):
+    def __init__(self, values, categories=None, ordered=False,
+                 name=None, fastpath=False):
 
         if fastpath:
             # fast path
@@ -245,17 +245,6 @@ def __init__(self, values, categories=None, ordered=False, name=None,
                    "name=\"something\")'")
             warn(msg, UserWarning, stacklevel=2)
 
-        # TODO: Remove after deprecation period in 2017/ after 0.18
-        if levels is not None:
-            warn("Creating a 'Categorical' with 'levels' is deprecated, use "
-                 "'categories' instead", FutureWarning, stacklevel=2)
-            if categories is None:
-                categories = levels
-            else:
-                raise ValueError("Cannot pass in both 'categories' and "
-                                 "(deprecated) 'levels', use only "
-                                 "'categories'", stacklevel=2)
-
         # sanitize input
         if is_categorical_dtype(values):
 
@@ -580,21 +569,6 @@ def _get_categories(self):
     categories = property(fget=_get_categories, fset=_set_categories,
                           doc=_categories_doc)
 
-    def _set_levels(self, levels):
-        """ set new levels (deprecated, use "categories") """
-        warn("Assigning to 'levels' is deprecated, use 'categories'",
-             FutureWarning, stacklevel=2)
-        self.categories = levels
-
-    def _get_levels(self):
-        """ Gets the levels (deprecated, use "categories") """
-        warn("Accessing 'levels' is deprecated, use 'categories'",
-             FutureWarning, stacklevel=2)
-        return self.categories
-
-    # TODO: Remove after deprecation period in 2017/ after 0.18
-    levels = property(fget=_get_levels, fset=_set_levels)
-
     _ordered = None
 
     def _set_ordered(self, value):

pandas/tests/test_categorical.py

@@ -1559,18 +1559,6 @@ def test_deprecated_labels(self):
             res = cat.labels
         self.assert_numpy_array_equal(res, exp)
 
-    def test_deprecated_levels(self):
-        # TODO: levels is deprecated and should be removed in 0.18 or 2017,
-        # whatever is earlier
-        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
-        exp = cat.categories
-        with tm.assert_produces_warning(FutureWarning):
-            res = cat.levels
-        self.assert_index_equal(res, exp)
-        with tm.assert_produces_warning(FutureWarning):
-            res = pd.Categorical([1, 2, 3, np.nan], levels=[1, 2, 3])
-        self.assert_index_equal(res.categories, exp)
-
     def test_removed_names_produces_warning(self):
 
         # 10482