Fix recursion depth limit when hashing numpy.datetime64

This fixes the bug described in [issue 534](#534).

Author: jcipar

deepdiff/helper.py

@@ -58,6 +58,7 @@ def __repr__(self):
     np_complex128 = np_type  # pragma: no cover.
     np_cdouble = np_type  # pragma: no cover.
     np_complexfloating = np_type  # pragma: no cover.
+    np_datetime64 = np_type  # pragma: no cover.
 else:
     np_array_factory = np.array
     np_ndarray = np.ndarray
@@ -80,6 +81,7 @@ def __repr__(self):
     np_complex128 = np.complex128
     np_cdouble = np.cdouble  # np.complex_ is an alias for np.cdouble and is being removed by NumPy 2.0
     np_complexfloating = np.complexfloating
+    np_datetime64 = np.datetime64
 
 numpy_numbers = (
     np_int8, np_int16, np_int32, np_int64, np_uint8,
@@ -93,6 +95,7 @@ def __repr__(self):
 
 numpy_dtypes = set(numpy_numbers)
 numpy_dtypes.add(np_bool_)  # type: ignore
+numpy_dtypes.add(np_datetime64)  # type: ignore
 
 numpy_dtype_str_to_type = {
     item.__name__: item for item in numpy_dtypes
@@ -184,10 +187,10 @@ def get_semvar_as_integer(version):
 bytes_type = bytes
 only_complex_number = (complex,) + numpy_complex_numbers
 only_numbers = (int, float, complex, Decimal) + numpy_numbers
-datetimes = (datetime.datetime, datetime.date, datetime.timedelta, datetime.time)
+datetimes = (datetime.datetime, datetime.date, datetime.timedelta, datetime.time, np_datetime64)
 ipranges = (ipaddress.IPv4Interface, ipaddress.IPv6Interface, ipaddress.IPv4Network, ipaddress.IPv6Network)
 uuids = (uuid.UUID, )
-times = (datetime.datetime, datetime.time)
+times = (datetime.datetime, datetime.time,np_datetime64)
 numbers: Tuple = only_numbers + datetimes
 booleans = (bool, np_bool_)
 

tests/test_diff_numpy.py

@@ -143,6 +143,25 @@
             }
         },
     },
+    'numpy_datetime_equal': {
+        't1': np.datetime64('2023-07-05T10:11:12'),
+        't2': np.datetime64('2023-07-05T10:11:12'),
+        'deepdiff_kwargs': {},
+        'expected_result': {},
+    },
+    'numpy_datetime_unequal': {
+        't1': np.datetime64('2023-07-05T10:11:12'),
+        't2': np.datetime64('2024-07-05T10:11:12'),
+        'deepdiff_kwargs': {},
+        'expected_result': {
+            'values_changed': {
+                'root': {
+                    'new_value': np.datetime64('2024-07-05T10:11:12'),
+                    'old_value': np.datetime64('2023-07-05T10:11:12'),
+                }
+            },
+        },
+    },
 }
 
 

tests/test_hash.py

@@ -196,6 +196,19 @@ def test_numpy_bool(self):
         a_hash = DeepHash(a)[a]
         assert not( a_hash is unprocessed)
 
+    def test_numpy_datetime64(self):
+        now_dt = datetime.datetime.now()
+        now = np.datetime64(now_dt)
+        later = np.datetime64(now_dt + datetime.timedelta(seconds=10))
+        a = b = now
+        a_hash = DeepHash(a)
+        b_hash = DeepHash(b)
+        assert a_hash[a] == b_hash[b]
+
+        later_hash = DeepHash(later)
+        assert a_hash[a] != later_hash[later]
+
+
 class TestDeepHashPrep:
     """DeepHashPrep Tests covering object serialization."""