From adcb30fbb1a7f16724afc332dfa673f251a5a5d7 Mon Sep 17 00:00:00 2001
From: Jean-Francois Zinque <jzinque@gmail.com>
Date: Mon, 27 Sep 2021 23:28:59 +0200
Subject: [PATCH 1/4] add test for all pandas-compatible numpy dtypes

---
 tests/core/test_dtypes.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/core/test_dtypes.py b/tests/core/test_dtypes.py
index dcb013b6b..32c1b2bc5 100644
--- a/tests/core/test_dtypes.py
+++ b/tests/core/test_dtypes.py
@@ -397,6 +397,28 @@ def test_default_numeric_dtypes():
     )
 
 
+@pytest.mark.parametrize(
+    "alias, np_dtype",
+    [
+        (alias, np_dtype)
+        for alias, np_dtype in np.sctypeDict.items()
+        # int, uint have different bitwidth under pandas and numpy.
+        if np_dtype != np.void and alias not in ("int", "uint")
+    ],
+)
+def test_numpy_dtypes(alias, np_dtype):
+    """Test that all pandas-compatible numpy dtypes are understood."""
+    try:
+        np.dtype(alias)
+    except TypeError:
+        # not a valid alias
+        assert pandas_engine.Engine.dtype(np_dtype)
+    else:
+        assert pandas_engine.Engine.dtype(alias) == pandas_engine.Engine.dtype(
+            np_dtype
+        )
+
+
 @pytest.mark.parametrize(
     "examples",
     [

From ca7375f4669650d0e309a97c3358b46fac2491bb Mon Sep 17 00:00:00 2001
From: Jean-Francois Zinque <jzinque@gmail.com>
Date: Mon, 27 Sep 2021 23:30:33 +0200
Subject: [PATCH 2/4] add support for np.bytes_

---
 pandera/engines/numpy_engine.py  | 11 +++++++++++
 pandera/engines/pandas_engine.py |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/pandera/engines/numpy_engine.py b/pandera/engines/numpy_engine.py
index c66bb5fc4..fa8c0b232 100644
--- a/pandera/engines/numpy_engine.py
+++ b/pandera/engines/numpy_engine.py
@@ -313,6 +313,17 @@ class Complex64(Complex128):
     bit_width: int = 64
 
 
+###############################################################################
+# bytes
+###############################################################################
+
+
+@Engine.register_dtype(equivalents=["bytes", bytes, np.bytes_])
+@immutable
+class Bytes(DataType):
+    type = np.dtype("bytes")
+
+
 ###############################################################################
 # string
 ###############################################################################
diff --git a/pandera/engines/pandas_engine.py b/pandera/engines/pandas_engine.py
index 9b0e9ca15..b3753e5dc 100644
--- a/pandera/engines/pandas_engine.py
+++ b/pandera/engines/pandas_engine.py
@@ -459,8 +459,11 @@ def check(self, pandera_dtype: dtypes.DataType) -> bool:
         "decimal",
         "mixed-integer",
         "mixed",
+        "bytes",
+        bytes,
         object,
         np.object_,
+        np.bytes_,
     ],
 )
 

From 59c0f8c5c85835888c1cab99f9be51ed720f6286 Mon Sep 17 00:00:00 2001
From: Jean-Francois Zinque <jzinque@gmail.com>
Date: Mon, 27 Sep 2021 23:31:15 +0200
Subject: [PATCH 3/4] add support for rare object aliases

---
 pandera/engines/pandas_engine.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandera/engines/pandas_engine.py b/pandera/engines/pandas_engine.py
index b3753e5dc..febf77560 100644
--- a/pandera/engines/pandas_engine.py
+++ b/pandera/engines/pandas_engine.py
@@ -454,6 +454,8 @@ def check(self, pandera_dtype: dtypes.DataType) -> bool:
     numpy_engine.Object,
     equivalents=[
         "object",
+        "object_",
+        "object0",
         "O",
         "bytes",
         "decimal",

From cc4f82c0171fe97dd9039bef470bfd84ae51832f Mon Sep 17 00:00:00 2001
From: Jean-Francois Zinque <jzinque@gmail.com>
Date: Mon, 27 Sep 2021 23:31:52 +0200
Subject: [PATCH 4/4] add support for platform-specific numpy dtypes

---
 pandera/engines/pandas_engine.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pandera/engines/pandas_engine.py b/pandera/engines/pandas_engine.py
index febf77560..44b11dcc4 100644
--- a/pandera/engines/pandas_engine.py
+++ b/pandera/engines/pandas_engine.py
@@ -137,7 +137,10 @@ def dtype(cls, data_type: Any) -> "DataType":
                 # into a numpy or pandas dtype.
                 np_or_pd_dtype = pd.api.types.pandas_dtype(data_type)
                 if isinstance(np_or_pd_dtype, np.dtype):
-                    np_or_pd_dtype = np_or_pd_dtype.type
+                    # cast alias to platform-agnostic dtype
+                    # e.g.: np.intc -> np.int32
+                    common_np_dtype = np.dtype(np_or_pd_dtype.name)
+                    np_or_pd_dtype = common_np_dtype.type
 
             return engine.Engine.dtype(cls, np_or_pd_dtype)