Location object creation from epw metadata (#821)

* * function location.Location.from_epw added. It permits to create a Location object from metadata of a epw file, typically retrieved with epw.read_epw().

* - Apply renaming suggestions with metadata and data

Author: tylunel

docs/sphinx/source/api.rst

@@ -376,6 +376,7 @@ in some files.
    :toctree: generated/
 
    location.Location.from_tmy
+   location.Location.from_epw
 
 
 TMY

docs/sphinx/source/whatsnew/v0.7.0.rst

@@ -140,6 +140,8 @@ Enhancements
   computing reductions in variability due to a spatially distributed plant.
 * Created one new incidence angle modifier (IAM) function for diffuse irradiance:
   :py:func:`pvlib.iam.martin_ruiz_diffuse`. (:issue:`751`)
+* Add :py:meth:`~pvlib.location.Location.from_epw`, a method to create a Location
+  object from epw metadata, typically coming from `pvlib.iotools.epw.read_epw`.
 
 Bug fixes
 ~~~~~~~~~

pvlib/location.py

@@ -125,6 +125,42 @@ def from_tmy(cls, tmy_metadata, tmy_data=None, **kwargs):
         # not sure if this should be assigned regardless of input.
         if tmy_data is not None:
             new_object.tmy_data = tmy_data
+            new_object.weather = tmy_data
+
+        return new_object
+
+    @classmethod
+    def from_epw(cls, metadata, data=None, **kwargs):
+        """
+        Create a Location object based on a metadata
+        dictionary from epw data readers.
+
+        Parameters
+        ----------
+        metadata : dict
+            Returned from epw.read_epw
+        data : None or DataFrame, default None
+            Optionally attach the epw data to this object.
+
+        Returns
+        -------
+        Location object (or the child class of Location that you
+        called this method from).
+        """
+
+        latitude = metadata['latitude']
+        longitude = metadata['longitude']
+
+        name = metadata['city']
+
+        tz = metadata['TZ']
+        altitude = metadata['altitude']
+
+        new_object = cls(latitude, longitude, tz=tz, altitude=altitude,
+                         name=name, **kwargs)
+
+        if data is not None:
+            new_object.weather = data
 
         return new_object
 

pvlib/test/test_location.py

@@ -218,7 +218,7 @@ def test_from_tmy_3():
     assert loc.name is not None
     assert loc.altitude != 0
     assert loc.tz != 'UTC'
-    assert_frame_equal(loc.tmy_data, data)
+    assert_frame_equal(loc.weather, data)
 
 
 def test_from_tmy_2():
@@ -229,7 +229,18 @@ def test_from_tmy_2():
     assert loc.name is not None
     assert loc.altitude != 0
     assert loc.tz != 'UTC'
-    assert_frame_equal(loc.tmy_data, data)
+    assert_frame_equal(loc.weather, data)
+
+
+def test_from_epw():
+    from test_epw import epw_testfile
+    from pvlib.iotools import read_epw
+    data, meta = read_epw(epw_testfile)
+    loc = Location.from_epw(meta, data)
+    assert loc.name is not None
+    assert loc.altitude != 0
+    assert loc.tz != 'UTC'
+    assert_frame_equal(loc.weather, data)
 
 
 def test_get_solarposition(expected_solpos, golden_mst):