Merge pull request #1238 from CartoDB/alasarr/cdf-fix-subclassing-1236

Fixing sublcassing issues

cartoframes/core/cartodataframe.py

@@ -18,6 +18,10 @@ def from_file(cls, filename, **kwargs):
         gdf = GeoDataFrame.from_file(filename, **kwargs)
         return cls(gdf)
 
+    @property
+    def _constructor(self):
+        return CartoDataFrame
+
     @classmethod
     def from_features(cls, features, **kwargs):
         gdf = GeoDataFrame.from_features(features, **kwargs)

tests/unit/core/test_cartodataframe.py

@@ -0,0 +1,26 @@
+"""Unit tests for cartoframes.data."""
+
+import geopandas as gpd
+from cartoframes import CartoDataFrame
+from shapely.geometry import box
+
+# DATA FRAME SRC BBOX
+pol_1 = box(1, 1, 2, 2)
+pol_2 = box(3, 3, 4, 4)
+GDF_BOX = gpd.GeoDataFrame({'id': [1, 2], 'geometry': [pol_1, pol_2]}, columns=['id', 'geometry'])
+
+
+class TestCartoDataFrame(object):
+
+    def test_basic_inheritance(self, mocker):
+        """Test basic inheritance"""
+        cdf = CartoDataFrame(GDF_BOX)
+        assert isinstance(cdf, CartoDataFrame)
+
+    def test_crs_inhericante(self, mocker):
+        """Test basic inheritance"""
+        cdf = CartoDataFrame(GDF_BOX)
+        cdf.crs = 'epsg:4326'
+        cdf = cdf.to_crs('epsg:3857')
+        assert isinstance(cdf, CartoDataFrame)
+        assert cdf.crs == 'epsg:3857'