handle warnings from temperature model tests (#796)

* handle warnings in temperature model tests

* test for content of exceptions

* test warning message content

* fix it up

* correct indent on asserts

* fix indent on pop

* fix exceptioninfo reference

* use match kwarg

* use match kwarg throughout

Author: cwhanse

pvlib/modelchain.py

@@ -324,13 +324,15 @@ def __init__(self, system, location,
         # TODO: deprecated kwarg temp_model. Remove use of temp_model in v0.8
         temp_model = kwargs.pop('temp_model', None)
         if temp_model is not None:
-            warnings.warn('The temp_model keyword argument is deprecated. Use '
-                          'temperature_model instead', pvlibDeprecationWarning)
             if temperature_model is None:
+                warnings.warn('The temp_model keyword argument is deprecated.'
+                              ' Use temperature_model instead',
+                              pvlibDeprecationWarning)
                 temperature_model = temp_model
             elif temp_model == temperature_model:
                 warnings.warn('Provide only one of temperature_model or '
-                              'temp_model (deprecated).')
+                              'temp_model (deprecated).',
+                              pvlibDeprecationWarning)
             else:
                 raise ValueError(
                     'Conflicting temperature_model {} and temp_model {}. '

pvlib/test/test_modelchain.py

@@ -470,10 +470,10 @@ def test_infer_aoi_model(location, system_no_aoi, aoi_model):
 
 
 def test_infer_aoi_model_invalid(location, system_no_aoi):
-    with pytest.raises(ValueError) as excinfo:
+    exc_text = 'could not infer AOI model'
+    with pytest.raises(ValueError, match=exc_text):
         ModelChain(system_no_aoi, location, orientation_strategy='None',
                    spectral_model='no_loss')
-    assert 'could not infer AOI model' in str(excinfo.value)
 
 
 def constant_spectral_loss(mc):
@@ -593,29 +593,26 @@ def test_deprecated_08():
     module_parameters = {'R_sh_ref': 1, 'a_ref': 1, 'I_o_ref': 1,
                          'alpha_sc': 1, 'I_L_ref': 1, 'R_s': 1}
     # do not assign PVSystem.temperature_model_parameters
+    # leave out PVSystem.racking_model and PVSystem.module_type
     system = PVSystem(module_parameters=module_parameters)
-    with pytest.warns(pvlibDeprecationWarning):
-        ModelChain(system, location,
-                   dc_model='desoto',
-                   aoi_model='no_loss', spectral_model='no_loss',
-                   temp_model='sapm',
-                   ac_model='snlinverter')
-    system = PVSystem(module_parameters=module_parameters)
-    with pytest.warns(pvlibDeprecationWarning):
-        ModelChain(system, location,
-                   dc_model='desoto',
-                   aoi_model='no_loss', spectral_model='no_loss',
-                   temperature_model='sapm',
-                   temp_model='sapm',
-                   ac_model='snlinverter')
-    system = PVSystem(module_parameters=module_parameters)
-    with pytest.raises(ValueError):
-        ModelChain(system, location,
-                   dc_model='desoto',
-                   aoi_model='no_loss', spectral_model='no_loss',
-                   temperature_model='pvsyst',
-                   temp_model='sapm',
-                   ac_model='snlinverter')
+    # deprecated temp_model kwarg
+    warn_txt = 'temp_model keyword argument is deprecated'
+    with pytest.warns(pvlibDeprecationWarning, match=warn_txt):
+        ModelChain(system, location, dc_model='desoto', aoi_model='no_loss',
+                   spectral_model='no_loss', ac_model='snlinverter',
+                   temp_model='sapm')
+    # provide both temp_model and temperature_model kwargs
+    warn_txt = 'Provide only one of temperature_model'
+    with pytest.warns(pvlibDeprecationWarning, match=warn_txt):
+        ModelChain(system, location, dc_model='desoto', aoi_model='no_loss',
+                   spectral_model='no_loss', ac_model='snlinverter',
+                   temperature_model='sapm', temp_model='sapm')
+    # conflicting temp_model and temperature_model kwargs
+    exc_text = 'Conflicting temperature_model'
+    with pytest.raises(ValueError, match=exc_text):
+        ModelChain(system, location, dc_model='desoto', aoi_model='no_loss',
+                   spectral_model='no_loss', ac_model='snlinverter',
+                   temperature_model='pvsyst', temp_model='sapm')
 
 
 @requires_scipy

pvlib/test/test_pvsystem.py

@@ -419,16 +419,20 @@ def test__infer_temperature_model_params():
     expected = temperature.TEMPERATURE_MODEL_PARAMETERS[
         'sapm']['open_rack_glass_polymer']
     assert expected == system._infer_temperature_model_params()
-    expected = temperature.TEMPERATURE_MODEL_PARAMETERS[
-        'pvsyst']['freestanding']
     system = pvsystem.PVSystem(module_parameters={},
                                racking_model='freestanding',
                                module_type='glass_polymer')
+    expected = temperature.TEMPERATURE_MODEL_PARAMETERS[
+        'pvsyst']['freestanding']
     assert expected == system._infer_temperature_model_params()
-    system = pvsystem.PVSystem(module_parameters={},
-                               racking_model='not_a_rack_model',
-                               module_type='glass_polymer')
-    assert {} == system._infer_temperature_model_params()
+
+
+def test__infer_temperature_model_params_deprec_warning():
+    warn_txt = "Reverting to deprecated default"
+    with pytest.warns(pvlibDeprecationWarning, match=warn_txt):
+        pvsystem.PVSystem(module_parameters={},
+                          racking_model='not_a_rack_model',
+                          module_type='glass_polymer')
 
 
 def test_calcparams_desoto(cec_module_params):