Fix bug where zero value for latitude/longitude causes error gh-171 (#176)

elodie/media/media.py

@@ -86,22 +86,29 @@ class Media(Base):
         # The lat/lon _keys array has an order of precedence.
         # The first key is writable and we will give the writable
         #   key precence when reading.
-        direction_multiplier = 1
+        direction_multiplier = 1.0
         for key in self.latitude_keys + self.longitude_keys:
+            if key not in exif:
+                continue
+
+            # Cast coordinate to a float due to a bug in exiftool's 
+            #   -json output format.
+            # https://github.com/jmathai/elodie/issues/171
+            # http://u88.n24.queensu.ca/exiftool/forum/index.php/topic,7952.0.html #noqa
+            this_coordinate = float(exif[key])
+
             # TODO: verify that we need to check ref key
             #   when self.set_gps_ref != True
-            if type == 'latitude' and key in self.latitude_keys and \
-                    key in exif:
+            if type == 'latitude' and key in self.latitude_keys:
                 if self.latitude_ref_key in exif and \
                         exif[self.latitude_ref_key] == 'S':
-                    direction_multiplier = -1
-                return exif[key] * direction_multiplier
-            elif type == 'longitude' and key in self.longitude_keys and \
-                    key in exif:
+                    direction_multiplier = -1.0
+                return this_coordinate * direction_multiplier
+            elif type == 'longitude' and key in self.longitude_keys:
                 if self.longitude_ref_key in exif and \
                         exif[self.longitude_ref_key] == 'W':
-                    direction_multiplier = -1
-                return exif[key] * direction_multiplier
+                    direction_multiplier = -1.0
+                return this_coordinate * direction_multiplier
 
         return None
 

elodie/tests/media/photo_test.py

@@ -101,6 +101,14 @@ def test_get_coordinates_without_exif():
     assert latitude is None, latitude
     assert longitude is None, longitude
 
+def test_get_coordinates_with_zero_coordinate():
+    photo = Photo(helper.get_file('with-location-zero-coordinate.jpg'))
+    latitude = photo.get_coordinate('latitude')
+    longitude = photo.get_coordinate('longitude')
+
+    assert helper.isclose(latitude,51.55325), latitude
+    assert helper.isclose(longitude,-0.00417777777778), longitude
+
 def test_get_date_taken():
     photo = Photo(helper.get_file('plain.jpg'))
     date_taken = photo.get_date_taken()