allow passing TileLayer to Map

folium/folium.py

@@ -97,9 +97,10 @@ class Map(JSCSSMixin, MacroElement):
         Width of the map.
     height: pixel int or percentage string (default: '100%')
         Height of the map.
-    tiles: str, default 'OpenStreetMap'
+    tiles: str or TileLayer, default 'OpenStreetMap'
         Map tileset to use. Can choose from a list of built-in tiles,
-        pass a custom URL or pass `None` to create a map without tiles.
+        pass a custom URL, pass a TileLayer object,
+        or pass `None` to create a map without tiles.
         For more advanced tile layer options, use the `TileLayer` class.
     min_zoom: int, default 0
         Minimum allowed zoom level for the tile layer that is created.
@@ -282,7 +283,9 @@ def __init__(
 
         self.objects_to_stay_in_front = []
 
-        if tiles:
+        if isinstance(tiles, TileLayer):
+            self.add_child(tiles)
+        elif tiles:
             tile_layer = TileLayer(tiles=tiles, attr=attr,
                                    min_zoom=min_zoom, max_zoom=max_zoom)
             self.add_child(tile_layer, name=tile_layer.tile_name)

tests/test_folium.py

@@ -10,6 +10,7 @@
 import branca.element
 
 import folium
+from folium import TileLayer
 from folium.features import GeoJson, Choropleth
 
 import jinja2
@@ -148,6 +149,13 @@ def test_custom_tile(self):
         bounds = m.get_bounds()
         assert bounds == [[None, None], [None, None]], bounds
 
+    def test_tilelayer_object(self):
+        url = "http://{s}.custom_tiles.org/{z}/{x}/{y}.png"
+        attr = "Attribution for custom tiles"
+        m = folium.Map(location=[45.52, -122.67], tiles=TileLayer(url, attr=attr))
+        assert next(iter(m._children.values())).tiles == url
+        assert attr in m._parent.render()
+
     def test_feature_group(self):
         """Test FeatureGroup."""