From 30c6e99bafbcee616ec5e3612a7b4dfabbf14d13 Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Tue, 19 Sep 2017 21:48:26 -0700
Subject: [PATCH 1/2] Remove properties from groupby whitelists

---
 pandas/core/groupby.py                 | 33 +++++++++++++++++---------
 pandas/tests/groupby/test_whitelist.py |  2 --
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/pandas/core/groupby.py b/pandas/core/groupby.py
index f14ed08a27fae..d6f8ba96696d6 100644
--- a/pandas/core/groupby.py
+++ b/pandas/core/groupby.py
@@ -168,10 +168,10 @@
 
 _series_apply_whitelist = ((_common_apply_whitelist |
                             {'nlargest', 'nsmallest'}) -
-                           {'boxplot'}) | frozenset(['dtype', 'unique'])
+                           {'boxplot'}) | frozenset(['unique'])
 
 _dataframe_apply_whitelist = ((_common_apply_whitelist |
-                              frozenset(['dtypes', 'corrwith'])) -
+                              frozenset(['corrwith'])) -
                               {'boxplot'})
 
 _cython_transforms = frozenset(['cumprod', 'cumsum', 'shift',
@@ -2782,13 +2782,6 @@ def _whitelist_method_generator(klass, whitelist):
     \"""
     f = %(self)s.__getattr__('%(name)s')
     return f(%(args)s)"""
-    property_wrapper_template = \
-        """@property
-def %(name)s(self) :
-    \"""
-    %(doc)s
-    \"""
-    return self.__getattr__('%(name)s')"""
     for name in whitelist:
         # don't override anything that was explicitly defined
         # in the base class
@@ -2811,8 +2804,8 @@ def %(name)s(self) :
                       'self': args[0],
                       'args': ','.join(args_by_name)}
         else:
-            wrapper_template = property_wrapper_template
-            params = {'name': name, 'doc': doc}
+            msg = 'property %s should be implemented directly.' % name
+            raise ValueError(msg)
         yield wrapper_template % params
 
 
@@ -2824,6 +2817,14 @@ class SeriesGroupBy(GroupBy):
                                                 _series_apply_whitelist):
         exec(_def_str)
 
+    @property
+    def dtype(self):
+        """
+         return the dtype object of the underlying data
+        """
+        self._set_group_selection()
+        return self.apply(lambda x: x.dtype)
+
     @property
     def _selection_name(self):
         """
@@ -3980,6 +3981,16 @@ class DataFrameGroupBy(NDFrameGroupBy):
 
     _block_agg_axis = 1
 
+    @property
+    def dtypes(self):
+        """
+        Return the dtypes in this object.
+        """
+        # need to setup the selection
+        # as are not passed directly but in the grouper
+        self._set_group_selection()
+        return self.apply(lambda x: x.dtypes)
+
     _agg_doc = dedent("""
     Examples
     --------
diff --git a/pandas/tests/groupby/test_whitelist.py b/pandas/tests/groupby/test_whitelist.py
index 1c5161d2ffb43..90eb3af3fa9bc 100644
--- a/pandas/tests/groupby/test_whitelist.py
+++ b/pandas/tests/groupby/test_whitelist.py
@@ -44,7 +44,6 @@
     'plot',
     'hist',
     'median',
-    'dtypes',
     'corrwith',
     'corr',
     'cov',
@@ -81,7 +80,6 @@
     'plot',
     'hist',
     'median',
-    'dtype',
     'corr',
     'cov',
     'diff',

From e137988667a1e05a4760d13631872ef413a4f401 Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Wed, 20 Sep 2017 20:43:53 -0700
Subject: [PATCH 2/2] Try to get more info in travis error message

---
 pandas/core/groupby.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/core/groupby.py b/pandas/core/groupby.py
index d6f8ba96696d6..230be08b4d8be 100644
--- a/pandas/core/groupby.py
+++ b/pandas/core/groupby.py
@@ -2805,7 +2805,7 @@ def _whitelist_method_generator(klass, whitelist):
                       'args': ','.join(args_by_name)}
         else:
             msg = 'property %s should be implemented directly.' % name
-            raise ValueError(msg)
+            raise ValueError(msg, type(f))
         yield wrapper_template % params