WIP - Bool Extension Array

pandas/core/arrays/boolean.py

@@ -0,0 +1,52 @@
+import numpy as np
+
+from pandas.core.arrays.integer import IntegerArray, _IntegerDtype
+from pandas.core.dtypes.dtypes import registry
+from pandas.util._decorators import cache_readonly
+
+
+class BooleanDtype(_IntegerDtype):
+    name = "EABool"
+    type = np.bool
+    na_value = np.nan
+
+    @cache_readonly
+    def is_signed_integer(self):
+        return False
+
+    @cache_readonly
+    def is_unsigned_integer(self):
+        return False
+
+    @classmethod
+    def construct_array_type(cls):
+        return BooleanArray
+
+
+class BooleanArray(IntegerArray):
+
+    @cache_readonly
+    def dtype(self):
+        return BooleanDtype()
+
+
+def to_boolean_array(values):
+    """
+    Infer and return an integer array of the values.
+
+    Parameters
+    ----------
+    values : 1D list-like
+
+    Returns
+    -------
+    IntegerArray
+
+    Raises
+    ------
+    TypeError if incompatible types
+    """
+    return BooleanArray(values, dtype='uint8', copy=False)
+
+
+registry.register(BooleanDtype)

pandas/core/arrays/integer.py

@@ -11,6 +11,7 @@
 from pandas.core.dtypes.generic import ABCSeries, ABCIndexClass
 from pandas.core.dtypes.common import (
     is_integer, is_scalar, is_float,
+    is_bool_dtype,
     is_float_dtype,
     is_integer_dtype,
     is_object_dtype,
@@ -158,7 +159,8 @@ def coerce_to_array(values, dtype, mask=None, copy=False):
             raise TypeError("{} cannot be converted to an IntegerDtype".format(
                 values.dtype))
 
-    elif not (is_integer_dtype(values) or is_float_dtype(values)):
+    elif not (is_integer_dtype(values) or is_float_dtype(values) or
+              is_bool_dtype(values)):
         raise TypeError("{} cannot be converted to an IntegerDtype".format(
             values.dtype))
 

pandas/tests/extension/base/dtype.py

@@ -13,6 +13,7 @@ def test_name(self, dtype):
 
     def test_kind(self, dtype):
         valid = set('biufcmMOSUV')
+
         if dtype.kind is not None:
             assert dtype.kind in valid