Isin

.gitignore

@@ -37,7 +37,7 @@ nosetests.xml
 .cache
 .ropeproject/
 .tags*
-.testmondata
+.testmon*
 .pytest_cache
 
 # asv environments
@@ -51,10 +51,11 @@ nosetests.xml
 .project
 .pydevproject
 
-# PyCharm and Vim
+# IDEs
 .idea
 *.swp
 .DS_Store
+.vscode/
 
 # xarray specific
 doc/_build

doc/api.rst

@@ -174,6 +174,7 @@ Computation
 :py:attr:`~Dataset.cumsum`
 :py:attr:`~Dataset.cumprod`
 :py:attr:`~Dataset.rank`
+:py:attr:`~Dataset.isin`
 
 **Grouped operations**:
 :py:attr:`~core.groupby.DatasetGroupBy.assign`
@@ -339,6 +340,7 @@ Computation
 :py:attr:`~DataArray.cumsum`
 :py:attr:`~DataArray.cumprod`
 :py:attr:`~DataArray.rank`
+:py:attr:`~DataArray.isin`
 
 **Grouped operations**:
 :py:attr:`~core.groupby.DataArrayGroupBy.assign_coords`

doc/whats-new.rst

@@ -37,7 +37,12 @@ Documentation
 Enhancements
 ~~~~~~~~~~~~
 
- - Some speed improvement to construct :py:class:`~xarray.DataArrayRolling`
+- `~xarray.DataArray.isin` and `~xarray.Dataset.isin` methods, which test each value 
+  in the array for whether it is contained in the supplied list, returning a bool array.
+   Similar to the ``np.isin`` function. Requires NumPy >= 1.13 
+By `Maximilian Roos <https://github.com/maxim-lian>`
+
+- Some speed improvement to construct :py:class:`~xarray.DataArrayRolling`
  object (:issue:`1993`)
  By `Keisuke Fujii <https://github.com/fujiisoup>`_.
  - Handle variables with different values for ``missing_value`` and

xarray/core/common.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import, division, print_function
 
 import warnings
+from distutils.version import LooseVersion
 
 import numpy as np
 import pandas as pd
@@ -744,6 +745,35 @@ def close(self):
             self._file_obj.close()
         self._file_obj = None
 
+    def isin(self, test_elements):
+        """Tests each value in the array for whether it is in the supplied list
+        Requires NumPy >= 1.13 
+
+        Parameters
+        ----------
+        element : array_like
+            Input array.
+        test_elements : array_like
+            The values against which to test each value of `element`.
+            This argument is flattened if an array or array_like.
+            See numpy notes for behavior with non-array-like parameters.
+
+        -------
+        isin : same as object, bool
+            Has the same shape as object
+        """
+        if LooseVersion(np.__version__) < LooseVersion('1.13.0'):
+            raise ImportError('isin requires numpy version 1.13.0 or later')
+        from .computation import apply_ufunc
+
+        return apply_ufunc(
+            np.isin,
+            self,
+            kwargs=dict(test_elements=test_elements),
+            dask='parallelized',
+            output_dtypes=[np.bool_],
+        )
+
     def __enter__(self):
         return self
 

xarray/tests/test_dataarray.py

@@ -3327,6 +3327,14 @@ def da(request):
             [0, np.nan, 1, 2, np.nan, 3, 4, 5, np.nan, 6, 7],
             dims='time')
 
+    if request.param == 'repeating_ints':
+        return DataArray(
+            np.tile(np.arange(12), 5).reshape(5, 4, 3),
+            coords={'x': list('abc'),
+                    'y': list('defg')},
+            dims=list('zyx')
+        )
+
 
 @pytest.fixture
 def da_dask(seed=123):
@@ -3339,6 +3347,31 @@ def da_dask(seed=123):
     return da
 
 
+@pytest.mark.skipif(LooseVersion(np.__version__) < LooseVersion('1.13.0'),
+                    reason='requires numpy version 1.13.0 or later')
+@pytest.mark.parametrize('da', ('repeating_ints', ), indirect=True)
+def test_isin(da):
+
+    expected = DataArray(
+        np.asarray([[0, 0, 0], [1, 0, 0]]),
+        dims=list('yx'),
+        coords={'x': list('abc'),
+                'y': list('de')},
+    ).astype('bool')
+
+    result = da.isin([3]).sel(y=list('de'), z=0)
+    assert_equal(result, expected)
+
+    expected = DataArray(
+        np.asarray([[0, 0, 1], [1, 0, 0]]),
+        dims=list('yx'),
+        coords={'x': list('abc'),
+                'y': list('de')},
+    ).astype('bool')
+    result = da.isin([2, 3]).sel(y=list('de'), z=0)
+    assert_equal(result, expected)
+
+
 @pytest.mark.parametrize('da', (1, 2), indirect=True)
 def test_rolling_iter(da):
 

xarray/tests/test_dataset.py

@@ -21,7 +21,7 @@
 
 from . import (
     InaccessibleArray, TestCase, UnexpectedDataAccess, assert_allclose,
-    assert_array_equal, assert_equal, assert_identical, raises_regex,
+    assert_array_equal, assert_equal, assert_identical, has_dask, raises_regex,
     requires_bottleneck, requires_dask, requires_scipy, source_ndarray)
 
 try:
@@ -4037,9 +4037,66 @@ def test_ipython_key_completion(self):
 # Py.test tests
 
 
-@pytest.fixture()
-def data_set(seed=None):
-    return create_test_data(seed)
+@pytest.fixture(params=[None])
+def data_set(request):
+    return create_test_data(request.param)
+
+
+@pytest.mark.skipif(LooseVersion(np.__version__) < LooseVersion('1.13.0'),
+                    reason='requires numpy version 1.13.0 or later')
+@pytest.mark.parametrize('test_elements', (
+    [1, 2],
+    np.array([1, 2]),
+    DataArray([1, 2]),
+    pytest.mark.xfail(Dataset({'x': [1, 2]})),
+))
+def test_isin(test_elements):
+    expected = Dataset(
+        data_vars={
+            'var1': (('dim1',), [0, 1]),
+            'var2': (('dim1',), [1, 1]),
+            'var3': (('dim1',), [0, 1]),
+        }
+    ).astype('bool')
+
+    result = Dataset(
+        data_vars={
+            'var1': (('dim1',), [0, 1]),
+            'var2': (('dim1',), [1, 2]),
+            'var3': (('dim1',), [0, 1]),
+        }
+    ).isin(test_elements)
+
+    assert_equal(result, expected)
+
+
+@pytest.mark.skipif(LooseVersion(np.__version__) < LooseVersion('1.13.0') or  # noqa
+                    not has_dask,  # noqa
+                    reason='requires dask and numpy version 1.13.0 or later')
+@pytest.mark.parametrize('test_elements', (
+    [1, 2],
+    np.array([1, 2]),
+    DataArray([1, 2]),
+    pytest.mark.xfail(Dataset({'x': [1, 2]})),
+))
+def test_isin_dask(test_elements):
+    expected = Dataset(
+        data_vars={
+            'var1': (('dim1',), [0, 1]),
+            'var2': (('dim1',), [1, 1]),
+            'var3': (('dim1',), [0, 1]),
+        }
+    ).astype('bool')
+
+    result = Dataset(
+        data_vars={
+            'var1': (('dim1',), [0, 1]),
+            'var2': (('dim1',), [1, 2]),
+            'var3': (('dim1',), [0, 1]),
+        }
+    ).chunk(1).isin(test_elements).compute()
+
+    assert_equal(result, expected)
 
 
 def test_dir_expected_attrs(data_set):

xarray/tests/test_variable.py

@@ -1422,8 +1422,6 @@ def test_reduce(self):
         with raises_regex(ValueError, 'cannot supply both'):
             v.mean(dim='x', axis=0)
 
-    @pytest.mark.skipif(LooseVersion(np.__version__) < LooseVersion('1.10.0'),
-                        reason='requires numpy version 1.10.0 or later')
     def test_quantile(self):
         v = Variable(['x', 'y'], self.d)
         for q in [0.25, [0.50], [0.25, 0.75]]: