BUG: fix read_file and to_file errors (geopandas#3628)

Author: jsignell

CHANGELOG.md

@@ -5,6 +5,7 @@
 Bug fixes:
 
 - Fix an issue that caused an error in `GeoDataFrame.from_features` when there is no `properties` field (#3599).
+- Fix `read_file` and `to_file` errors (#3682)
 
 ## Version 1.1.1 (June 27, 2025)
 

geopandas/io/file.py

@@ -101,7 +101,7 @@ def _check_pyogrio(func):
         raise ImportError(
             f"the {func} requires the 'pyogrio' package, but it is not installed "
             "or does not import correctly."
-            "\nImporting pyogrio resulted in: {pyogrio_import_error}"
+            f"\nImporting pyogrio resulted in: {pyogrio_import_error}"
         )
 
 

geopandas/io/tests/test_file.py

@@ -1514,6 +1514,40 @@ def test_error_engine_unavailable_fiona(tmp_path, df_points, file_path):
         df_points.to_file(tmp_path / "test.gpkg", engine="fiona")
 
 
+def test_error_monkeypatch_engine_unavailable_pyogrio(
+    monkeypatch, tmp_path, df_points, file_path
+) -> None:
+    # monkeypatch to make pyogrio unimportable
+    monkeypatch.setattr(geopandas.io.file, "_import_pyogrio", lambda: None)
+    monkeypatch.setattr(geopandas.io.file, "pyogrio", None)
+    monkeypatch.setattr(
+        geopandas.io.file, "pyogrio_import_error", "No module named 'pyogrio'"
+    )
+
+    with pytest.raises(ImportError, match="No module named 'pyogrio'"):
+        geopandas.read_file(file_path, engine="pyogrio")
+
+    with pytest.raises(ImportError, match="No module named 'pyogrio'"):
+        df_points.to_file(tmp_path / "test.gpkg", engine="pyogrio")
+
+
+def test_error_monkeypatch_engine_unavailable_fiona(
+    monkeypatch, tmp_path, df_points, file_path
+) -> None:
+    # monkeypatch to make fiona unimportable
+    monkeypatch.setattr(geopandas.io.file, "_import_fiona", lambda: None)
+    monkeypatch.setattr(geopandas.io.file, "fiona", None)
+    monkeypatch.setattr(
+        geopandas.io.file, "fiona_import_error", "No module named 'fiona'"
+    )
+
+    with pytest.raises(ImportError, match="No module named 'fiona'"):
+        geopandas.read_file(file_path, engine="fiona")
+
+    with pytest.raises(ImportError, match="No module named 'fiona'"):
+        df_points.to_file(tmp_path / "test.gpkg", engine="fiona")
+
+
 @PYOGRIO_MARK
 def test_list_layers(df_points, tmpdir):
     tempfilename = os.path.join(str(tmpdir), "dataset.gpkg")