ModelChainResult.__repr__ (#1236)

* initial __repr__ for ModelChainResult

* fix timezone handling

* working on it

* working now

* jettison that space

* whatsnew

* inline comments

* shorten it up

* test, add ModelChain.__repr__ test also

* remove unneeded decorator

Author: cwhanse

docs/sphinx/source/whatsnew/v0.10.0.rst

@@ -31,6 +31,8 @@ Enhancements
 ~~~~~~~~~~~~
 * Added `map_variables` parameter to :py:func:`pvlib.iotools.read_srml`
   and :py:func:`pvlib.iotools.read_srml_month_from_solardat` (:pull:`1773`)
+* Improved `ModelChainResult.__repr__` (:pull:`1236`)
+
 
 Bug fixes
 ~~~~~~~~~
@@ -55,3 +57,5 @@ Contributors
 ~~~~~~~~~~~~
 * Taos Transue (:ghuser:`reepoi`)
 * Adam R. Jensen (:ghuser:`AdamRJensen`)
+* Cliff Hansen (:ghuser:`cwhanse`)
+

pvlib/modelchain.py

@@ -253,6 +253,33 @@ def get_orientation(strategy, **kwargs):
     return surface_tilt, surface_azimuth
 
 
+def _getmcattr(self, attr):
+    """
+    Helper for __repr__ methods, needed to avoid recursion in property
+    lookups
+    """
+    out = getattr(self, attr)
+    try:
+        out = out.__name__
+    except AttributeError:
+        pass
+    return out
+
+
+def _mcr_repr(obj):
+    '''
+    Helper for ModelChainResult.__repr__
+    '''
+    if isinstance(obj, tuple):
+        return "Tuple (" + ", ".join([_mcr_repr(o) for o in obj]) + ")"
+    if isinstance(obj, pd.DataFrame):
+        return "DataFrame ({} rows x {} columns)".format(*obj.shape)
+    if isinstance(obj, pd.Series):
+        return "Series (length {})".format(len(obj))
+    # scalar, None, other?
+    return repr(obj)
+
+    
 # Type for fields that vary between arrays
 T = TypeVar('T')
 
@@ -384,6 +411,33 @@ def __setattr__(self, key, value):
             value = self._result_type(value)
         super().__setattr__(key, value)
 
+    def __repr__(self):
+        mc_attrs = dir(self)
+
+        def _head(obj):
+            try:
+                return obj[:3]
+            except:
+                return obj
+
+        if type(self.dc) is tuple:
+            num_arrays = len(self.dc)
+        else:
+            num_arrays = 1
+
+        desc1 = ('=== ModelChainResult === \n')
+        desc2 = (f'Number of Arrays: {num_arrays} \n')
+        attr = 'times'
+        desc3 = ('times (first 3)\n' +
+                 f'{_head(_getmcattr(self, attr))}' +
+                 '\n')
+        lines = []
+        for attr in mc_attrs:
+            if not (attr.startswith('_') or attr=='times'):
+                lines.append(f' {attr}: ' + _mcr_repr(getattr(self, attr)))
+        desc4 = '\n'.join(lines)
+        return (desc1 + desc2 + desc3 + desc4)
+
 
 class ModelChain:
     """
@@ -650,18 +704,8 @@ def __repr__(self):
             'airmass_model', 'dc_model', 'ac_model', 'aoi_model',
             'spectral_model', 'temperature_model', 'losses_model'
         ]
-
-        def getmcattr(self, attr):
-            """needed to avoid recursion in property lookups"""
-            out = getattr(self, attr)
-            try:
-                out = out.__name__
-            except AttributeError:
-                pass
-            return out
-
         return ('ModelChain: \n  ' + '\n  '.join(
-            f'{attr}: {getmcattr(self, attr)}' for attr in attrs))
+            f'{attr}: {_getmcattr(self, attr)}' for attr in attrs))
 
     @property
     def dc_model(self):

pvlib/tests/test_modelchain.py

@@ -1987,3 +1987,36 @@ def test__irrad_for_celltemp():
     assert len(poa) == 2
     assert_series_equal(poa[0], effect_irrad)
     assert_series_equal(poa[1], effect_irrad)
+
+
+def test_ModelChain___repr__(sapm_dc_snl_ac_system, location):
+
+    mc = ModelChain(sapm_dc_snl_ac_system, location,
+                    name='my mc')
+
+    expected = '\n'.join([
+        'ModelChain: ',
+        '  name: my mc',
+        '  clearsky_model: ineichen',
+        '  transposition_model: haydavies',
+        '  solar_position_method: nrel_numpy',
+        '  airmass_model: kastenyoung1989',
+        '  dc_model: sapm',
+        '  ac_model: sandia_inverter',
+        '  aoi_model: sapm_aoi_loss',
+        '  spectral_model: sapm_spectral_loss',
+        '  temperature_model: sapm_temp',
+        '  losses_model: no_extra_losses'
+    ])
+
+    assert mc.__repr__() == expected
+
+
+def test_ModelChainResult___repr__(sapm_dc_snl_ac_system, location, weather):
+    mc = ModelChain(sapm_dc_snl_ac_system, location)
+    mc.run_model(weather)
+    mcres = mc.results.__repr__()
+    mc_attrs = dir(mc.results)
+    mc_attrs = [a for a in mc_attrs if not a.startswith('_')]
+    assert all([a in mcres for a in mc_attrs])
+