Merge #195

195: fix pandas v2.1 NumpyEADtype issue r=andrewgsavage a=topper-123

- [x] Closes #194
- [x] Executed `pre-commit run --all-files` with no errors
- [x] The change is fully covered by automated unit tests
- [ ] Documented in docs/ as appropriate
- [ ] Added an entry to the CHANGES file

Precursor to working on #174.


Co-authored-by: Terji Petersen <terji78@gmail.com>

pint_pandas/pint_array.py

@@ -2,6 +2,7 @@
 import re
 import warnings
 from collections import OrderedDict
+from importlib.metadata import version
 
 import numpy as np
 import pandas as pd
@@ -27,6 +28,11 @@
 # quantify/dequantify
 NO_UNIT = "No Unit"
 
+pandas_version = version("pandas")
+pandas_version_info = tuple(
+    int(x) if x.isdigit() else x for x in pandas_version.split(".")
+)
+
 
 class PintType(ExtensionDtype):
     """
@@ -185,6 +191,12 @@ def __repr__(self):
         return self.name
 
 
+_NumpyEADtype = (
+    pd.core.dtypes.dtypes.PandasDtype
+    if pandas_version_info < (2, 1)
+    else pd.core.dtypes.dtypes.NumpyEADtype
+)
+
 dtypemap = {
     int: pd.Int64Dtype(),
     np.int64: pd.Int64Dtype(),
@@ -195,8 +207,8 @@ def __repr__(self):
     float: pd.Float64Dtype(),
     np.float64: pd.Float64Dtype(),
     np.float32: pd.Float32Dtype(),
-    np.complex128: pd.core.dtypes.dtypes.PandasDtype("complex128"),
-    np.complex64: pd.core.dtypes.dtypes.PandasDtype("complex64"),
+    np.complex128: _NumpyEADtype("complex128"),
+    np.complex64: _NumpyEADtype("complex64"),
     # np.float16: pd.Float16Dtype(),
 }
 dtypeunmap = {v: k for k, v in dtypemap.items()}
@@ -458,7 +470,8 @@ def take(self, indices, allow_fill=False, fill_value=None):
         Examples
         --------
         """
-        from pandas.core.algorithms import take, is_scalar
+        from pandas.core.algorithms import take
+        from pandas.api.types import is_scalar
 
         data = self._data
         if allow_fill and fill_value is None:

pint_pandas/testsuite/test_pandas_extensiontests.py

@@ -343,7 +343,7 @@ def _check_divmod_op(self, s, op, other, exc=None):
                 divmod(s, other)
 
     def _get_exception(self, data, op_name):
-        if data.data.dtype == pd.core.dtypes.dtypes.PandasDtype("complex128"):
+        if data.data.dtype == dtypemap[np.complex128]:
             if op_name in ["__floordiv__", "__rfloordiv__", "__mod__", "__rmod__"]:
                 return op_name, TypeError
         if op_name in ["__pow__", "__rpow__"]: