Use pandas wrapper functions for the test suite (#1021)

* add wrapper functions for pandas testing asserts

* update tests to use assert wrapper instead of importing from pandas.testing

* update wrappers

* refactor asserts

* update basic_chain test values

* whatsnew

* add test

Author: kandersolar

docs/sphinx/source/whatsnew/v0.8.0.rst

@@ -53,6 +53,9 @@ Testing
   (:pull:`1006`)
 * Update the `data/test_psm3_tmy-2017.csv` datafile to match the updated
   NSRDB data. (:issue:`1005`, :pull:`1007`)
+* Add wrappers around the pandas assert_X_equal functions to accommodate the
+  changed API and default precision thresholds in pandas 1.1.0
+  (:issue:`1018`, :pull:`1021`)
 
 Documentation
 ~~~~~~~~~~~~~

pvlib/tests/conftest.py

@@ -35,6 +35,38 @@ def inner(*args, **kwargs):
         return inner
     return wrapper
 
+
+def _check_pandas_assert_kwargs(kwargs):
+    # handles the change in API related to default
+    # tolerances in pandas 1.1.0.  See pvlib GH #1018
+    if parse_version(pd.__version__) >= parse_version('1.1.0'):
+        if kwargs.pop('check_less_precise', False):
+            kwargs['atol'] = 1e-3
+            kwargs['rtol'] = 1e-3
+        else:
+            kwargs['atol'] = 1e-5
+            kwargs['rtol'] = 1e-5
+    else:
+        kwargs.pop('rtol', None)
+        kwargs.pop('atol', None)
+    return kwargs
+
+
+def assert_index_equal(left, right, **kwargs):
+    kwargs = _check_pandas_assert_kwargs(kwargs)
+    pd.testing.assert_index_equal(left, right, **kwargs)
+
+
+def assert_series_equal(left, right, **kwargs):
+    kwargs = _check_pandas_assert_kwargs(kwargs)
+    pd.testing.assert_series_equal(left, right, **kwargs)
+
+
+def assert_frame_equal(left, right, **kwargs):
+    kwargs = _check_pandas_assert_kwargs(kwargs)
+    pd.testing.assert_frame_equal(left, right, **kwargs)
+
+
 # commonly used directories in the tests
 TEST_DIR = Path(__file__).parent
 DATA_DIR = TEST_DIR.parent / 'data'

pvlib/tests/iotools/test_crn.py

@@ -1,5 +1,5 @@
 import pandas as pd
-from pandas.testing import assert_frame_equal
+from conftest import assert_frame_equal
 import numpy as np
 from numpy import dtype, nan
 import pytest

pvlib/tests/iotools/test_solrad.py

@@ -1,5 +1,5 @@
 import pandas as pd
-from pandas.testing import assert_frame_equal
+from conftest import assert_frame_equal
 import numpy as np
 from numpy import nan
 

pvlib/tests/test_atmosphere.py

@@ -4,7 +4,7 @@
 from numpy import nan
 from numpy.testing import assert_allclose
 import pandas as pd
-from pandas.testing import assert_series_equal
+from conftest import assert_series_equal
 import pytest
 
 from pvlib import atmosphere

pvlib/tests/test_bifacial.py

@@ -1,7 +1,7 @@
 import pandas as pd
 from datetime import datetime
 from pvlib.bifacial import pvfactors_timeseries
-from conftest import requires_pvfactors
+from conftest import requires_pvfactors, assert_series_equal
 import pytest
 
 
@@ -49,8 +49,8 @@ def test_pvfactors_timeseries():
         rho_front_pvrow=rho_front_pvrow, rho_back_pvrow=rho_back_pvrow,
         horizon_band_angle=horizon_band_angle)
 
-    pd.testing.assert_series_equal(ipoa_inc_front, expected_ipoa_front)
-    pd.testing.assert_series_equal(ipoa_inc_back, expected_ipoa_back)
+    assert_series_equal(ipoa_inc_front, expected_ipoa_front)
+    assert_series_equal(ipoa_inc_back, expected_ipoa_back)
 
 
 @requires_pvfactors
@@ -97,5 +97,5 @@ def test_pvfactors_timeseries_pandas_inputs():
         rho_front_pvrow=rho_front_pvrow, rho_back_pvrow=rho_back_pvrow,
         horizon_band_angle=horizon_band_angle)
 
-    pd.testing.assert_series_equal(ipoa_inc_front, expected_ipoa_front)
-    pd.testing.assert_series_equal(ipoa_inc_back, expected_ipoa_back)
+    assert_series_equal(ipoa_inc_front, expected_ipoa_front)
+    assert_series_equal(ipoa_inc_back, expected_ipoa_back)

pvlib/tests/test_clearsky.py

@@ -7,7 +7,7 @@
 
 import pytest
 from numpy.testing import assert_allclose
-from pandas.testing import assert_frame_equal, assert_series_equal
+from conftest import assert_frame_equal, assert_series_equal
 
 from pvlib.location import Location
 from pvlib import clearsky

pvlib/tests/test_conftest.py

@@ -1,5 +1,7 @@
 import pytest
+import pandas
 
+import conftest
 from conftest import fail_on_pvlib_version
 
 from pvlib._deprecation import pvlibDeprecationWarning, deprecated
@@ -43,3 +45,38 @@ def test_use_fixture_with_decorator(some_data):
     assert some_data == "some data"
     with pytest.warns(pvlibDeprecationWarning):  # test for deprecation warning
         deprec_func(some_data)
+
+
+@pytest.mark.parametrize('function_name', ['assert_index_equal',
+                                           'assert_series_equal',
+                                           'assert_frame_equal'])
+@pytest.mark.parametrize('pd_version', ['1.0.0', '1.1.0'])
+@pytest.mark.parametrize('check_less_precise', [True, False])
+def test__check_pandas_assert_kwargs(mocker, monkeypatch,
+                                     function_name, pd_version,
+                                     check_less_precise):
+    # test that conftest._check_pandas_assert_kwargs returns appropriate
+    # kwargs for the assert_x_equal functions
+
+    # patch the pandas assert; not interested in actually calling them:
+    def patched_assert(*args, **kwargs):
+        pass
+
+    monkeypatch.setattr(pandas.testing, function_name, patched_assert)
+    # then attach a spy to it so we can see what args it is called with:
+    mocked_function = mocker.spy(pandas.testing, function_name)
+    # patch pd.__version__ to exercise the two branches in
+    # conftest._check_pandas_assert_kwargs
+    monkeypatch.setattr(pandas, '__version__', pd_version)
+
+    # finally, run the function and check what args got passed to pandas:
+    assert_function = getattr(conftest, function_name)
+    args = [None, None]
+    assert_function(*args, check_less_precise=check_less_precise)
+    if pd_version == '1.1.0':
+        tol = 1e-3 if check_less_precise else 1e-5
+        expected_kwargs = {'atol': tol, 'rtol': tol}
+    else:
+        expected_kwargs = {'check_less_precise': check_less_precise}
+
+    mocked_function.assert_called_with(*args, **expected_kwargs)

pvlib/tests/test_iam.py

@@ -9,7 +9,7 @@
 import pandas as pd
 
 import pytest
-from pandas.testing import assert_series_equal
+from conftest import assert_series_equal
 from numpy.testing import assert_allclose
 
 from pvlib import iam as _iam

pvlib/tests/test_inverter.py

@@ -3,7 +3,7 @@
 import numpy as np
 import pandas as pd
 
-from pandas.testing import assert_series_equal
+from conftest import assert_series_equal
 from numpy.testing import assert_allclose
 
 from pvlib import inverter