fixups

Author: TomAugspurger

pandas/core/dtypes/dtypes.py

@@ -199,7 +199,7 @@ def __eq__(self, other):
             return hash(self) == hash(other)
 
     def __unicode__(self):
-        tpl = 'CategoricalDtype({}, ordered={})'
+        tpl = 'CategoricalDtype({}ordered={})'
         if self.categories is None:
             data = "None"
         else:

pandas/core/internals.py

@@ -137,15 +137,14 @@ def is_categorical_astype(self, dtype):
         validate that we have a astypeable to categorical,
         returns a boolean if we are a categorical
         """
-        if is_categorical_dtype(dtype):
-            if dtype == CategoricalDtype():
-                return True
-
-        elif dtype is Categorical:
+        if dtype is Categorical or dtype is CategoricalDtype:
             # this is a pd.Categorical, but is not
             # a valid type for astypeing
             raise TypeError("invalid type {0} for astype".format(dtype))
 
+        elif is_categorical_dtype(dtype):
+            return True
+
         return False
 
     def external_values(self, dtype=None):
@@ -491,7 +490,9 @@ def _astype(self, dtype, copy=False, errors='raise', values=None,
             if (('categories' in kwargs or 'ordered' in kwargs) and
                     isinstance(dtype, CategoricalDtype)):
                 raise TypeError("Cannot specify a CategoricalDtype and also "
-                                "`categories` or `ordered`")
+                                "`categories` or `ordered`. Use "
+                                "`dtype=CategoricalDtype(categories, ordered)`"
+                                " instead.")
             kwargs = kwargs.copy()
             categories = getattr(dtype, 'categories', None)
             ordered = getattr(dtype, 'ordered', False)

pandas/tests/series/test_analytics.py

@@ -1724,7 +1724,6 @@ class TestNLargestNSmallest(object):
               # not supported on some archs
               # Series([3., 2, 1, 2, 5], dtype='complex256'),
               Series([3., 2, 1, 2, 5], dtype='complex128'),
-              Series(list('abcde'), dtype='category'),
               Series(list('abcde'))])
     def test_error(self, r):
         dt = r.dtype
@@ -1736,6 +1735,16 @@ def test_error(self, r):
             with tm.assert_raises_regex(TypeError, msg):
                 method(arg)
 
+    def test_error_categorical_dtype(self):
+        # same as test_error, but regex hard to escape properly
+        msg = ("Cannot use method 'n(larg|small)est' with dtype "
+               "CategoricalDtype.+")
+        with tm.assert_raises_regex(TypeError, msg):
+            Series(list('ab'), dtype='category').nlargest(2)
+
+        with tm.assert_raises_regex(TypeError, msg):
+            Series(list('ab'), dtype='category').nsmallest(2)
+
     @pytest.mark.parametrize(
         "s",
         [v for k, v in s_main_dtypes().iteritems()])

pandas/tests/test_config.py

@@ -2,7 +2,6 @@
 import pytest
 
 import pandas as pd
-import pandas.util.testing as tm
 
 import warnings
 
@@ -429,8 +428,3 @@ def test_option_context_scope(self):
 
         # Ensure the current context is reset
         assert self.cf.get_option(option_name) == original_value
-
-    def test_html_border_deprecated(self):
-        with tm.assert_produces_warning(FutureWarning):
-            with pd.option_context("html.border", 0):
-                pass