BUG: Escape special characters in explore (#2657) (#2658)

CHANGELOG.md

@@ -17,6 +17,7 @@ Bug fixes:
 - Ensure that GeoDataFrame created from DataFrame is a copy, not a view (#2667)
 - Fix mismatch between geometries and colors in ``plot()`` if an empty or missing
   geometry is present (#2224)
+- Escape special characters to avoid TemplateSyntaxError in ``explore()`` (#2657)
 - Fix `to_parquet`/`to_feather` to not write an invalid bbox (with NaNs) in the
   metadata in case of an empty GeoDataFrame (#2653)
 

geopandas/explore.py

@@ -278,6 +278,7 @@ GON (((180.00000 -16.06713, 180.00000...
     try:
         import branca as bc
         import folium
+        import re
         import matplotlib
         import matplotlib.colors as colors
         import matplotlib.pyplot as plt
@@ -618,10 +619,21 @@ GON (((180.00000 -16.06713, 180.00000...
     else:
         tooltip = None
         popup = None
+    # escape the curly braces {{}} for jinja2 templates
+    feature_collection = gdf.__geo_interface__
+    for feature in feature_collection["features"]:
+        for k in feature["properties"]:
+            # escape the curly braces in values
+            if type(feature["properties"][k]) == str:
+                feature["properties"][k] = re.sub(
+                    r"\{{2,}",
+                    lambda x: "{% raw %}" + x.group(0) + "{% endraw %}",
+                    feature["properties"][k],
+                )
 
     # add dataframe to map
     folium.GeoJson(
-        gdf.__geo_interface__,
+        feature_collection,
         tooltip=tooltip,
         popup=popup,
         marker=marker,

geopandas/tests/test_explore.py

@@ -466,6 +466,15 @@ class TestExplore:
         out_str = self._fetch_map_string(m)
         assert "BoroName" in out_str
 
+    def test_escape_special_characters(self):
+        # check if special characters are escaped
+        gdf = self.world.copy()
+        gdf["name"] = """{{{what a mess}}} they are so different."""
+        m = gdf.explore()
+        out_str = self._fetch_map_string(m)
+        assert """{{{""" in out_str
+        assert """}}}""" in out_str
+
     def test_default_markers(self):
         # check overridden default for points
         m = self.cities.explore()