From ff5d593de8750b7bf81bdf8af810cbded6e24c7e Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Tue, 21 Dec 2021 16:05:46 -0800
Subject: [PATCH 1/3] ENH: implement EADtype.empty

---
 pandas/core/dtypes/base.py                  | 14 ++++++++++++++
 pandas/tests/extension/base/constructors.py |  8 +++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/pandas/core/dtypes/base.py b/pandas/core/dtypes/base.py
index 372abee701b02..afd0d69e7e829 100644
--- a/pandas/core/dtypes/base.py
+++ b/pandas/core/dtypes/base.py
@@ -17,6 +17,7 @@
 from pandas._libs.hashtable import object_hash
 from pandas._typing import (
     DtypeObj,
+    Shape,
     npt,
     type_t,
 )
@@ -208,6 +209,19 @@ def construct_array_type(cls) -> type_t[ExtensionArray]:
         """
         raise AbstractMethodError(cls)
 
+    def empty(self, shape: Shape) -> type_t[ExtensionArray]:
+        """
+        Construct an ExtensionArray of this dtype with the given shape.
+
+        Analogous to numpy.empty.
+
+        Returns
+        -------
+        ExtensionArray
+        """
+        cls = self.construct_array_type()
+        return cls._empty(shape, dtype=self)
+
     @classmethod
     def construct_from_string(
         cls: type_t[ExtensionDtypeT], string: str
diff --git a/pandas/tests/extension/base/constructors.py b/pandas/tests/extension/base/constructors.py
index 4ba315eeaeb15..c86054aed7e4d 100644
--- a/pandas/tests/extension/base/constructors.py
+++ b/pandas/tests/extension/base/constructors.py
@@ -126,6 +126,12 @@ def test_construct_empty_dataframe(self, dtype):
     def test_empty(self, dtype):
         cls = dtype.construct_array_type()
         result = cls._empty((4,), dtype=dtype)
-
         assert isinstance(result, cls)
         assert result.dtype == dtype
+        assert result.shape == (4,)
+
+        # GH#19600 method on ExtensionDtype
+        result2 = dtype.empty((4,))
+        assert isinstance(result2, cls)
+        assert result2.dtype == dtype
+        assert result2.shape == (4,)

From 78b0e71fe63bc45b43ba7885ca0cdcce69f1e3b9 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 22 Dec 2021 18:46:31 -0800
Subject: [PATCH 2/3] ENH: implement EA._hasnans

---
 pandas/core/arrays/base.py | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 8bcdd42b9f795..274be2a6a434b 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -425,7 +425,7 @@ def __contains__(self, item: object) -> bool | np.bool_:
             if not self._can_hold_na:
                 return False
             elif item is self.dtype.na_value or isinstance(item, self.dtype.type):
-                return self.isna().any()
+                return self._hasnans
             else:
                 return False
         else:
@@ -603,6 +603,16 @@ def isna(self) -> np.ndarray | ExtensionArraySupportsAnyAll:
         """
         raise AbstractMethodError(self)
 
+    @property
+    def _hasnans(self) -> bool:
+        # GH#22680
+        """
+        Equivalent to `self.isna().any()`.
+
+        Some ExtensionArray subclasses may be able to optimize this check.
+        """
+        return self.isna().any()
+
     def _values_for_argsort(self) -> np.ndarray:
         """
         Return values for sorting.
@@ -686,7 +696,7 @@ def argmin(self, skipna: bool = True) -> int:
         ExtensionArray.argmax
         """
         validate_bool_kwarg(skipna, "skipna")
-        if not skipna and self.isna().any():
+        if not skipna and self._hasnans:
             raise NotImplementedError
         return nargminmax(self, "argmin")
 
@@ -710,7 +720,7 @@ def argmax(self, skipna: bool = True) -> int:
         ExtensionArray.argmin
         """
         validate_bool_kwarg(skipna, "skipna")
-        if not skipna and self.isna().any():
+        if not skipna and self._hasnans:
             raise NotImplementedError
         return nargminmax(self, "argmax")
 

From 14a103a1863241165b93ee25c4272e390fdfedb9 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Thu, 23 Dec 2021 08:17:07 -0800
Subject: [PATCH 3/3] mypy fixup

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

diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 274be2a6a434b..fc915f5f84d8b 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -611,7 +611,7 @@ def _hasnans(self) -> bool:
 
         Some ExtensionArray subclasses may be able to optimize this check.
         """
-        return self.isna().any()
+        return bool(self.isna().any())
 
     def _values_for_argsort(self) -> np.ndarray:
         """