From a3a2ee25242269844757ad2526ace3cd8e85089b Mon Sep 17 00:00:00 2001
From: Tom Augspurger <tom.w.augspurger@gmail.com>
Date: Wed, 4 Oct 2017 10:41:23 -0500
Subject: [PATCH] Return dtype, not type

---
 pandas/core/dtypes/cast.py | 12 ++++++------
 pandas/core/internals.py   | 35 ++++++++++++++++++-----------------
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 0096783d1dddb5..9b7877cc072803 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -483,8 +483,8 @@ def infer_dtype_from_array(arr, pandas_dtype=False):
     return arr.dtype, arr
 
 
-def _maybe_infer_dtype_type(element):
-    """Try to infer an object's dtype's type, for use in arithmetic ops
+def maybe_infer_dtype_type(element):
+    """Try to infer an object's dtype, for use in arithmetic ops
 
     Uses `element.dtype` if that's available.
     Objects implementing the iterator protocol are cast to a NumPy array,
@@ -503,16 +503,16 @@ def _maybe_infer_dtype_type(element):
     Examples
     --------
     >>> from collections import namedtuple
-    >>> Foo = namedtuple("dtype")
-    >>> _maybe_infer_dtype_type(Foo(np.dtype("i8")))
+    >>> Foo = namedtuple("Foo", "dtype")
+    >>> maybe_infer_dtype_type(Foo(np.dtype("i8")))
     numpy.int64
     """
     tipo = None
     if hasattr(element, 'dtype'):
-        tipo = element.dtype.type
+        tipo = element.dtype
     elif is_list_like(element):
         element = np.asarray(element)
-        tipo = element.dtype.type
+        tipo = element.dtype
     return tipo
 
 
diff --git a/pandas/core/internals.py b/pandas/core/internals.py
index b6f8fc5fef853e..945afc432eef79 100644
--- a/pandas/core/internals.py
+++ b/pandas/core/internals.py
@@ -45,7 +45,7 @@
     maybe_convert_objects,
     astype_nansafe,
     find_common_type,
-    _maybe_infer_dtype_type)
+    maybe_infer_dtype_type)
 from pandas.core.dtypes.missing import (
     isna, notna, array_equivalent,
     _isna_compat,
@@ -630,9 +630,9 @@ def convert(self, copy=True, **kwargs):
     def _can_hold_element(self, element):
         """ require the same dtype as ourselves """
         dtype = self.values.dtype.type
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return issubclass(tipo, dtype)
+            return issubclass(tipo.type, dtype)
         return isinstance(element, dtype)
 
     def _try_cast_result(self, result, dtype=None):
@@ -1806,10 +1806,10 @@ class FloatBlock(FloatOrComplexBlock):
     _downcast_dtype = 'int64'
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return (issubclass(tipo, (np.floating, np.integer)) and
-                    not issubclass(tipo, (np.datetime64, np.timedelta64)))
+            return (issubclass(tipo.type, (np.floating, np.integer)) and
+                    not issubclass(tipo.type, (np.datetime64, np.timedelta64)))
         return (isinstance(element, (float, int, np.floating, np.int_)) and
                 not isinstance(element, (bool, np.bool_, datetime, timedelta,
                                          np.datetime64, np.timedelta64)))
@@ -1855,9 +1855,9 @@ class ComplexBlock(FloatOrComplexBlock):
     is_complex = True
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return issubclass(tipo,
+            return issubclass(tipo.type,
                               (np.floating, np.integer, np.complexfloating))
         return (isinstance(element,
                            (float, int, complex, np.float_, np.int_)) and
@@ -1873,11 +1873,12 @@ class IntBlock(NumericBlock):
     _can_hold_na = False
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return (issubclass(tipo, np.integer) and
-                    not issubclass(tipo, (np.datetime64, np.timedelta64)) and
-                    self.dtype.itemsize >= element.dtype.itemsize)
+            return (issubclass(tipo.type, np.integer) and
+                    not issubclass(tipo.type, (np.datetime64,
+                                               np.timedelta64)) and
+                    self.dtype.itemsize >= tipo.itemsize)
         return is_integer(element)
 
     def should_store(self, value):
@@ -1915,9 +1916,9 @@ def _box_func(self):
         return lambda x: tslib.Timedelta(x, unit='ns')
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return issubclass(tipo, np.timedelta64)
+            return issubclass(tipo.type, np.timedelta64)
         return isinstance(element, (timedelta, np.timedelta64))
 
     def fillna(self, value, **kwargs):
@@ -2015,9 +2016,9 @@ class BoolBlock(NumericBlock):
     _can_hold_na = False
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
-            return issubclass(tipo, np.bool_)
+            return issubclass(tipo.type, np.bool_)
         return isinstance(element, (bool, np.bool_))
 
     def should_store(self, value):
@@ -2447,7 +2448,7 @@ def _astype(self, dtype, mgr=None, **kwargs):
         return super(DatetimeBlock, self)._astype(dtype=dtype, **kwargs)
 
     def _can_hold_element(self, element):
-        tipo = _maybe_infer_dtype_type(element)
+        tipo = maybe_infer_dtype_type(element)
         if tipo:
             # TODO: this still uses asarray, instead of dtype.type
             element = np.array(element)