Merge pull request #1234 from gboeing/convert

improve graph_from_gdfs input checks

.pre-commit-config.yaml

@@ -35,14 +35,14 @@ repos:
         args: [--disable=MD013]
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: "v0.7.0"
+    rev: "v0.7.3"
     hooks:
       - id: ruff
         args: [--fix]
       - id: ruff-format
 
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: "v1.12.1"
+    rev: "v1.13.0"
     hooks:
       - id: mypy
         additional_dependencies:

osmnx/convert.py

@@ -222,6 +222,65 @@ def _make_edge_geometry(
     raise ValueError(msg)
 
 
+def _validate_node_edge_gdfs(
+    gdf_nodes: gpd.GeoDataFrame,
+    gdf_edges: gpd.GeoDataFrame,
+) -> None:
+    """
+    Validate that node/edge GeoDataFrames can be converted to a MultiDiGraph.
+
+    Raises a `ValueError` if validation fails.
+
+    Parameters
+    ----------
+    gdf_nodes
+        GeoDataFrame of graph nodes uniquely indexed by `osmid`.
+    gdf_edges
+        GeoDataFrame of graph edges uniquely multi-indexed by `(u, v, key)`.
+    graph_attrs
+
+    Returns
+    -------
+    None
+    """
+    # ensure gdf_nodes contains x and y columns representing node geometries
+    if not ("x" in gdf_nodes.columns and "y" in gdf_nodes.columns):  # pragma: no cover
+        msg = "`gdf_nodes` must contain 'x' and 'y' columns."
+        raise ValueError(msg)
+
+    # ensure gdf_nodes and gdf_edges are uniquely indexed
+    if not (gdf_nodes.index.is_unique and gdf_edges.index.is_unique):  # pragma: no cover
+        msg = "`gdf_nodes` and `gdf_edges` must each be uniquely indexed."
+        raise ValueError(msg)
+
+    # ensure 1) gdf_edges are multi-indexed with 3 levels and 2) that its u
+    # and v values (first two index levels) all appear among gdf_nodes index
+    edges_index_levels = 3
+    check1 = gdf_edges.index.nlevels == edges_index_levels
+    uv = set(gdf_edges.index.get_level_values(0)) | set(gdf_edges.index.get_level_values(1))
+    check2 = uv.issubset(set(gdf_nodes.index))
+    if not (check1 and check2):  # pragma: no cover
+        msg = "`gdf_edges` must be multi-indexed by `(u, v, key)`."
+        raise ValueError(msg)
+
+    # warn user if geometry values differ from coordinates in x/y columns,
+    # because we discard the geometry column
+    if gdf_nodes.active_geometry_name is not None:  # pragma: no cover
+        msg = (
+            "Discarding the `gdf_nodes` 'geometry' column, though its values "
+            "differ from the coordinates in the 'x' and 'y' columns."
+        )
+        try:
+            all_x_match = (gdf_nodes.geometry.x == gdf_nodes["x"]).all()
+            all_y_match = (gdf_nodes.geometry.y == gdf_nodes["y"]).all()
+            if not (all_x_match and all_y_match):
+                # warn if x/y coords don't match geometry column
+                warn(msg, category=UserWarning, stacklevel=2)
+        except ValueError:  # pragma: no cover
+            # warn if geometry column contains non-point geometry types
+            warn(msg, category=UserWarning, stacklevel=2)
+
+
 def graph_from_gdfs(
     gdf_nodes: gpd.GeoDataFrame,
     gdf_edges: gpd.GeoDataFrame,
@@ -258,31 +317,15 @@ def graph_from_gdfs(
     -------
     G
     """
-    if not ("x" in gdf_nodes.columns and "y" in gdf_nodes.columns):  # pragma: no cover
-        msg = "`gdf_nodes` must contain 'x' and 'y' columns."
-        raise ValueError(msg)
-
-    if not hasattr(gdf_nodes, "geometry"):
-        msg = "`gdf_nodes` must have a 'geometry' attribute."
-        raise ValueError(msg)
+    _validate_node_edge_gdfs(gdf_nodes, gdf_edges)
 
-    # drop geometry column from gdf_nodes (as we use x and y for geometry
+    # drop geometry column from gdf_nodes (since we use x and y for geometry
     # information), but warn the user if the geometry values differ from the
     # coordinates in the x and y columns. this results in a df instead of gdf.
-    msg = (
-        "Discarding the `gdf_nodes` 'geometry' column, though its values "
-        "differ from the coordinates in the 'x' and 'y' columns."
-    )
-    try:
-        all_x_match = (gdf_nodes.geometry.x == gdf_nodes["x"]).all()
-        all_y_match = (gdf_nodes.geometry.y == gdf_nodes["y"]).all()
-        if not (all_x_match and all_y_match):
-            # warn if x/y coords don't match geometry column
-            warn(msg, category=UserWarning, stacklevel=2)
-    except ValueError:  # pragma: no cover
-        # warn if geometry column contains non-point geometry types
-        warn(msg, category=UserWarning, stacklevel=2)
-    df_nodes = gdf_nodes.drop(columns=gdf_nodes.geometry.name)
+    if gdf_nodes.active_geometry_name is None:  # pragma: no cover
+        df_nodes = pd.DataFrame(gdf_nodes)
+    else:
+        df_nodes = gdf_nodes.drop(columns=gdf_nodes.active_geometry_name)
 
     # create graph and add graph-level attribute dict
     if graph_attrs is None: