Fix topojson object path

folium/features.py

@@ -24,6 +24,7 @@
     get_bounds,
     get_obj_in_upper_tree,
     image_to_url,
+    javascript_identifier_path_to_array_notation,
     none_max,
     none_min,
     parse_options,
@@ -901,7 +902,7 @@ class TopoJson(JSCSSMixin, Layer):
             var {{ this.get_name() }} = L.geoJson(
                 topojson.feature(
                     {{ this.get_name() }}_data,
-                    {{ this.get_name() }}_data.{{ this.object_path }}
+                    {{ this.get_name() }}_data{{ this._safe_object_path }}
                 ),
                 {
                 {%- if this.smooth_factor is not none %}
@@ -949,6 +950,9 @@ def __init__(
             self.data = data
 
         self.object_path = object_path
+        self._safe_object_path = javascript_identifier_path_to_array_notation(
+            object_path
+        )
 
         if style_function is None:
 

folium/utilities.py

@@ -493,3 +493,12 @@ def parse_options(**kwargs):
 def escape_backticks(text):
     """Escape backticks so text can be used in a JS template."""
     return re.sub(r"(?<!\\)`", r"\`", text)
+
+
+def escape_double_quotes(text):
+    return text.replace('"', r"\"")
+
+
+def javascript_identifier_path_to_array_notation(path):
+    """Convert a path like obj1.obj2 to array notation: ["obj1"]["obj2"]."""
+    return "".join(f'["{escape_double_quotes(x)}"]' for x in path.split("."))

tests/test_utilities.py

@@ -7,8 +7,10 @@
     _is_url,
     camelize,
     deep_copy,
+    escape_double_quotes,
     get_obj_in_upper_tree,
     if_pandas_df_convert_to_numpy,
+    javascript_identifier_path_to_array_notation,
     parse_options,
     validate_location,
     validate_locations,
@@ -189,3 +191,27 @@ def test_parse_options():
 )
 def test_is_url(url):
     assert _is_url(url) is True
+
+
+@pytest.mark.parametrize(
+    "text,result",
+    [
+        ("bla", "bla"),
+        ('bla"bla', r"bla\"bla"),
+        ('"bla"bla"', r"\"bla\"bla\""),
+    ],
+)
+def test_escape_double_quotes(text, result):
+    assert escape_double_quotes(text) == result
+
+
+@pytest.mark.parametrize(
+    "text,result",
+    [
+        ("bla", '["bla"]'),
+        ("obj-1.obj2", '["obj-1"]["obj2"]'),
+        ('obj-1.obj"2', r'["obj-1"]["obj\"2"]'),
+    ],
+)
+def test_javascript_identifier_path_to_array_notation(text, result):
+    assert javascript_identifier_path_to_array_notation(text) == result