MAINT: drop support for GDAL < 3.6 (#584)

theroggy · web-flow · commit 53e5bd90c120 · 2025-10-22T17:04:43.000+02:00
diff --git a/.github/workflows/docker-gdal.yml b/.github/workflows/docker-gdal.yml
@@ -26,8 +26,6 @@ jobs:
           - "ghcr.io/osgeo/gdal:ubuntu-small-3.8.5" # python 3.10.12
           - "ghcr.io/osgeo/gdal:ubuntu-small-3.7.3" # python 3.10.12
           - "ghcr.io/osgeo/gdal:ubuntu-small-3.6.4" # python 3.10.6
-          - "osgeo/gdal:ubuntu-small-3.5.3" # python 3.10 (installed manually)
-          - "osgeo/gdal:ubuntu-small-3.4.3" # python 3.10 (installed manually)
 
     container:
       image: ${{ matrix.container }}
@@ -37,14 +35,14 @@ jobs:
         run: |
           apt-get update && apt-get install -y build-essential git python3-dev
 
-      - name: Install Python
-        # the GDAL 3.4 and 3.5 images do have Python 3.8 installed, so have to
-        # install a more recent Python version manually
-        if: matrix.container == 'osgeo/gdal:ubuntu-small-3.5.3' || matrix.container == 'osgeo/gdal:ubuntu-small-3.4.3'
-        run: |
-          apt-get update && apt-get install -y software-properties-common
-          add-apt-repository -y ppa:deadsnakes/ppa
-          apt-get update && apt-get install -y python3.10-dev
+      # - name: Install Python
+      #   # the GDAL 3.4 and 3.5 images do have Python 3.8 installed, so have to
+      #   # install a more recent Python version manually
+      #   if: matrix.container == 'osgeo/gdal:ubuntu-small-3.5.3' || matrix.container == 'osgeo/gdal:ubuntu-small-3.4.3'
+      #   run: |
+      #     apt-get update && apt-get install -y software-properties-common
+      #     add-apt-repository -y ppa:deadsnakes/ppa
+      #     apt-get update && apt-get install -y python3.9-dev
 
       - uses: actions/checkout@v5
 
@@ -63,13 +61,8 @@ jobs:
       - name: Install Python Dependencies
         run: |
           uv pip install -e .[dev,test,geopandas]
-
-      - name: Install pyarrow
-        # GDAL>=3.6 required to use Arrow API
-        if: matrix.container != 'osgeo/gdal:ubuntu-small-3.5.3' && matrix.container != 'osgeo/gdal:ubuntu-small-3.4.3'
-        run: |
           uv pip install pyarrow
-
+          
       - name: Test with pytest
         run: |
           pytest --cov=pyogrio --cov-report term-missing pyogrio/tests
diff --git a/.github/workflows/tests-conda.yml b/.github/workflows/tests-conda.yml
@@ -35,11 +35,6 @@ jobs:
           - os: "ubuntu-latest"
             python: "3.10"
             env: "minimal"
-          # environment for older Windows libgdal to make sure gdal_i.lib is
-          # properly detected
-          - os: "windows-2022"
-            python: "3.10"
-            env: "libgdal3.5.1"
           # environment with nightly wheels
           - os: "ubuntu-latest"
             python: "3.11"
diff --git a/CHANGES.md b/CHANGES.md
@@ -6,6 +6,7 @@
 
 -   Return JSON fields (as identified by GDAL) as dicts/lists in `read_dataframe`;
     these were previously returned as strings (#556).
+-   Drop support for GDAL 3.4 and 3.5 (#584).
 
 ### Improvements
 
diff --git a/README.md b/README.md
@@ -26,7 +26,7 @@ Read the documentation for more information:
 
 ## Requirements
 
-Supports Python 3.10 - 3.14 and GDAL 3.4.x - 3.11.x.
+Supports Python 3.10 - 3.14 and GDAL 3.6.x - 3.11.x.
 
 Reading to GeoDataFrames requires `geopandas>=0.12` with `shapely>=2`.
 
diff --git a/ci/envs/libgdal3.5.1.yml b/ci/envs/libgdal3.5.1.yml
diff --git a/docs/source/install.md b/docs/source/install.md
@@ -2,7 +2,7 @@
 
 ## Requirements
 
-Supports Python 3.10 - 3.14 and GDAL 3.4.x - 3.11.x
+Supports Python 3.10 - 3.14 and GDAL 3.6.x - 3.11.x
 
 Reading to GeoDataFrames requires `geopandas>=0.12` with `shapely>=2`.
 
@@ -132,20 +132,20 @@ To build on Windows, you need to provide additional environment variables or
 command-line parameters because the location of the GDAL binaries and headers
 cannot be automatically determined.
 
-Assuming GDAL 3.4.1 is installed to `c:\GDAL`, you can set the `GDAL_INCLUDE_PATH`,
+Assuming GDAL 3.8.3 is installed to `c:\GDAL`, you can set the `GDAL_INCLUDE_PATH`,
 `GDAL_LIBRARY_PATH` and `GDAL_VERSION` environment variables and build as follows:
 
 ```bash
 set GDAL_INCLUDE_PATH=C:\GDAL\include
 set GDAL_LIBRARY_PATH=C:\GDAL\lib
-set GDAL_VERSION=3.4.1
+set GDAL_VERSION=3.8.3
 python -m pip install --no-deps --force-reinstall --no-use-pep517 -e . -v
 ```
 
 Alternatively, you can pass those options also as command-line parameters:
 
 ```bash
-python -m pip install --install-option=build_ext --install-option="-IC:\GDAL\include" --install-option="-lgdal_i" --install-option="-LC:\GDAL\lib" --install-option="--gdalversion=3.4.1" --no-deps --force-reinstall --no-use-pep517 -e . -v
+python -m pip install --install-option=build_ext --install-option="-IC:\GDAL\include" --install-option="-lgdal_i" --install-option="-LC:\GDAL\lib" --install-option="--gdalversion=3.8.3" --no-deps --force-reinstall --no-use-pep517 -e . -v
 ```
 
 The location of the GDAL DLLs must be on your system `PATH`.
diff --git a/pyogrio/_compat.py b/pyogrio/_compat.py
@@ -29,7 +29,6 @@
     pandas = None
 
 
-HAS_ARROW_API = __gdal_version__ >= (3, 6, 0)
 HAS_ARROW_WRITE_API = __gdal_version__ >= (3, 8, 0)
 HAS_PYARROW = pyarrow is not None
 HAS_PYPROJ = pyproj is not None
@@ -44,8 +43,6 @@
 PANDAS_GE_22 = pandas is not None and Version(pandas.__version__) >= Version("2.2.0")
 PANDAS_GE_30 = pandas is not None and Version(pandas.__version__) >= Version("3.0.0dev")
 
-GDAL_GE_350 = __gdal_version__ >= (3, 5, 0)
-GDAL_GE_352 = __gdal_version__ >= (3, 5, 2)
 GDAL_GE_37 = __gdal_version__ >= (3, 7, 0)
 GDAL_GE_38 = __gdal_version__ >= (3, 8, 0)
 GDAL_GE_311 = __gdal_version__ >= (3, 11, 0)
diff --git a/pyogrio/_io.pyx b/pyogrio/_io.pyx
@@ -1620,9 +1620,6 @@ def ogr_open_arrow(
     cdef ArrowArrayStream* stream
     cdef ArrowSchema schema
 
-    IF CTE_GDAL_VERSION < (3, 6, 0):
-        raise RuntimeError("Need GDAL>=3.6 for Arrow support")
-
     if force_2d:
         raise ValueError("forcing 2D is not supported for Arrow")
 
diff --git a/pyogrio/_ogr.pxd b/pyogrio/_ogr.pxd
@@ -418,14 +418,10 @@ cdef extern from "ogr_api.h":
     const char*     OLCFastGetExtent
     const char*     OLCTransactions
 
-
-IF CTE_GDAL_VERSION >= (3, 6, 0):
-
-    cdef extern from "ogr_api.h":
-        bint OGR_L_GetArrowStream(
-            OGRLayerH hLayer, ArrowArrayStream *out_stream, char** papszOptions
-        )
-
+cdef extern from "ogr_api.h":
+    bint OGR_L_GetArrowStream(
+        OGRLayerH hLayer, ArrowArrayStream *out_stream, char** papszOptions
+    )
 
 IF CTE_GDAL_VERSION >= (3, 8, 0):
 
diff --git a/pyogrio/_ogr.pyx b/pyogrio/_ogr.pyx
@@ -1,6 +1,5 @@
 import os
 import sys
-from uuid import uuid4
 import warnings
 
 from pyogrio._err cimport check_pointer
@@ -44,21 +43,16 @@ def get_gdal_version_string():
     return get_string(version)
 
 
-IF CTE_GDAL_VERSION >= (3, 4, 0):
-
-    cdef extern from "ogr_api.h":
-        bint OGRGetGEOSVersion(int *pnMajor, int *pnMinor, int *pnPatch)
+cdef extern from "ogr_api.h":
+    bint OGRGetGEOSVersion(int *pnMajor, int *pnMinor, int *pnPatch)
 
 
 def get_gdal_geos_version():
     cdef int major, minor, revision
 
-    IF CTE_GDAL_VERSION >= (3, 4, 0):
-        if not OGRGetGEOSVersion(&major, &minor, &revision):
-            return None
-        return (major, minor, revision)
-    ELSE:
+    if not OGRGetGEOSVersion(&major, &minor, &revision):
         return None
+    return (major, minor, revision)
 
 
 def set_gdal_config_options(dict options):
@@ -167,7 +161,7 @@ def get_gdal_data_path():
     """
     cdef const char *path_c = CPLFindFile("gdal", "header.dxf")
     if path_c != NULL:
-        return get_string(path_c).rstrip("header.dxf")
+        return get_string(path_c).replace("header.dxf", "")
     return None
 
 
diff --git a/pyogrio/raw.py b/pyogrio/raw.py
@@ -4,7 +4,7 @@
 from io import BytesIO
 from pathlib import Path
 
-from pyogrio._compat import HAS_ARROW_API, HAS_ARROW_WRITE_API, HAS_PYARROW
+from pyogrio._compat import HAS_ARROW_WRITE_API, HAS_PYARROW
 from pyogrio._env import GDALEnv
 from pyogrio.core import detect_write_driver
 from pyogrio.errors import DataSourceError
@@ -435,9 +435,6 @@ def open_arrow(
         }
 
     """
-    if not HAS_ARROW_API:
-        raise RuntimeError("GDAL>= 3.6 required to read using arrow")
-
     dataset_kwargs = _preprocess_options_key_value(kwargs) if kwargs else {}
 
     return ogr_open_arrow(
@@ -581,12 +578,6 @@ def _get_write_path_driver(path, driver, append=False):
             f"{get_gdal_version_string()}"
         )
 
-    # prevent segfault from: https://github.com/OSGeo/gdal/issues/5739
-    if append and driver == "FlatGeobuf" and get_gdal_version() <= (3, 5, 0):
-        raise RuntimeError(
-            "append to FlatGeobuf is not supported for GDAL <= 3.5.0 due to segfault"
-        )
-
     return path, driver
 
 
diff --git a/pyogrio/tests/conftest.py b/pyogrio/tests/conftest.py
@@ -11,7 +11,6 @@
 )
 from pyogrio._compat import (
     GDAL_GE_37,
-    HAS_ARROW_API,
     HAS_ARROW_WRITE_API,
     HAS_GDAL_GEOS,
     HAS_PYARROW,
@@ -66,10 +65,7 @@ def pytest_report_header(config):
 
 
 # marks to skip tests if optional dependecies are not present
-requires_arrow_api = pytest.mark.skipif(not HAS_ARROW_API, reason="GDAL>=3.6 required")
-requires_pyarrow_api = pytest.mark.skipif(
-    not HAS_ARROW_API or not HAS_PYARROW, reason="GDAL>=3.6 and pyarrow required"
-)
+requires_pyarrow_api = pytest.mark.skipif(not HAS_PYARROW, reason="pyarrow required")
 
 requires_pyproj = pytest.mark.skipif(not HAS_PYPROJ, reason="pyproj required")
 
diff --git a/pyogrio/tests/test_arrow.py b/pyogrio/tests/test_arrow.py
@@ -476,10 +476,6 @@ def test_write_geojson(tmp_path, naturalearth_lowres):
 
 
 @requires_arrow_write_api
-@pytest.mark.skipif(
-    __gdal_version__ < (3, 6, 0),
-    reason="OpenFileGDB write support only available for GDAL >= 3.6.0",
-)
 @pytest.mark.parametrize(
     "write_int64",
     [
@@ -643,7 +639,7 @@ def test_write_append(request, tmp_path, naturalearth_lowres, ext):
     assert read_info(filename)["features"] == 354
 
 
-@pytest.mark.parametrize("driver,ext", [("GML", ".gml"), ("GeoJSONSeq", ".geojsons")])
+@pytest.mark.parametrize("driver,ext", [("GML", ".gml")])
 @requires_arrow_write_api
 def test_write_append_unsupported(tmp_path, naturalearth_lowres, driver, ext):
     meta, table = read_arrow(naturalearth_lowres)
@@ -961,9 +957,6 @@ def test_write_memory_driver_required(naturalearth_lowres):
 @requires_arrow_write_api
 @pytest.mark.parametrize("driver", ["ESRI Shapefile", "OpenFileGDB"])
 def test_write_memory_unsupported_driver(naturalearth_lowres, driver):
-    if driver == "OpenFileGDB" and __gdal_version__ < (3, 6, 0):
-        pytest.skip("OpenFileGDB write support only available for GDAL >= 3.6.0")
-
     meta, table = read_arrow(naturalearth_lowres, max_features=1)
 
     buffer = BytesIO()
diff --git a/pyogrio/tests/test_core.py b/pyogrio/tests/test_core.py
@@ -18,7 +18,7 @@
     vsi_rmtree,
     vsi_unlink,
 )
-from pyogrio._compat import GDAL_GE_38, GDAL_GE_350
+from pyogrio._compat import GDAL_GE_38
 from pyogrio._env import GDALEnv
 from pyogrio.errors import DataLayerError, DataSourceError
 from pyogrio.raw import read, write
@@ -140,11 +140,7 @@ def test_list_drivers():
     # verify that the core drivers are present
     for name in ("ESRI Shapefile", "GeoJSON", "GeoJSONSeq", "GPKG", "OpenFileGDB"):
         assert name in all_drivers
-
         expected_capability = "rw"
-        if name == "OpenFileGDB" and __gdal_version__ < (3, 6, 0):
-            expected_capability = "r"
-
         assert all_drivers[name] == expected_capability
 
     drivers = list_drivers(read=True)
@@ -396,10 +392,6 @@ def test_read_bounds_mask(naturalearth_lowres_all_ext, mask, expected):
     assert array_equal(fids, fids_expected)
 
 
-@pytest.mark.skipif(
-    __gdal_version__ < (3, 4, 0),
-    reason="Cannot determine if GEOS is present or absent for GDAL < 3.4",
-)
 def test_read_bounds_bbox_intersects_vs_envelope_overlaps(naturalearth_lowres_all_ext):
     # If GEOS is present and used by GDAL, bbox filter will be based on intersection
     # of bbox and actual geometries; if GEOS is absent or not used by GDAL, it
@@ -587,11 +579,7 @@ def test_read_info_jsonfield(nested_geojson_file):
     """Test if JSON fields types are returned correctly."""
     meta = read_info(nested_geojson_file)
     assert meta["ogr_types"] == ["OFTString", "OFTString"]
-    if GDAL_GE_350:
-        # OFSTJSON is only supported for GDAL >= 3.5
-        assert meta["ogr_subtypes"] == ["OFSTNone", "OFSTJSON"]
-    else:
-        assert meta["ogr_subtypes"] == ["OFSTNone", "OFSTNone"]
+    assert meta["ogr_subtypes"] == ["OFSTNone", "OFSTJSON"]
 
 
 def test_read_info_unspecified_layer_warning(data_dir):
diff --git a/pyogrio/tests/test_geopandas_io.py b/pyogrio/tests/test_geopandas_io.py
@@ -20,8 +20,6 @@
 from pyogrio._compat import (
     GDAL_GE_37,
     GDAL_GE_311,
-    GDAL_GE_350,
-    GDAL_GE_352,
     HAS_ARROW_WRITE_API,
     HAS_PYPROJ,
     PANDAS_GE_15,
@@ -272,10 +270,6 @@ def test_read_force_2d(tmp_path, use_arrow):
     assert not df.iloc[0].geometry.has_z
 
 
-@pytest.mark.skipif(
-    not GDAL_GE_352,
-    reason="gdal >= 3.5.2 needed to use OGR_GEOJSON_MAX_OBJ_SIZE with a float value",
-)
 def test_read_geojson_error(naturalearth_lowres_geojson, use_arrow):
     try:
         set_gdal_config_options({"OGR_GEOJSON_MAX_OBJ_SIZE": 0.01})
@@ -387,10 +381,6 @@ def test_read_datetime_tz(datetime_tz_file, tmp_path, use_arrow):
     assert_series_equal(df_read.datetime_col, expected)
 
 
-@pytest.mark.skipif(
-    not GDAL_GE_350,
-    reason="OFSTJSON subtype + some list type situations need GDAL >= 3.5",
-)
 def test_read_list_types(list_field_values_file, use_arrow):
     """Test reading a geojson file containing fields with lists."""
     info = read_info(list_field_values_file)
@@ -1439,12 +1429,6 @@ def test_write_dataframe_gpkg_multiple_layers(tmp_path, naturalearth_lowres, use
 @pytest.mark.parametrize("ext", ALL_EXTS)
 @pytest.mark.requires_arrow_write_api
 def test_write_dataframe_append(request, tmp_path, naturalearth_lowres, ext, use_arrow):
-    if ext == ".fgb" and __gdal_version__ <= (3, 5, 0):
-        pytest.skip("Append to FlatGeobuf fails for GDAL <= 3.5.0")
-
-    if ext in (".geojsonl", ".geojsons") and __gdal_version__ <= (3, 6, 0):
-        pytest.skip("Append to GeoJSONSeq only available for GDAL >= 3.6.0")
-
     if use_arrow and ext.startswith(".geojson"):
         # Bug in GDAL when appending int64 to GeoJSON
         # (https://github.com/OSGeo/gdal/issues/9792)
@@ -2088,9 +2072,6 @@ def test_read_multisurface(multisurface_file, use_arrow):
         assert df.geometry.type.tolist() == ["MultiPolygon"]
 
 
-@pytest.mark.skipif(
-    not GDAL_GE_350, reason="OFSTJSON subtype only supported for GDAL >= 3.5"
-)
 def test_read_dataset_kwargs(nested_geojson_file, use_arrow):
     # by default, nested data are not flattened
     df = read_dataframe(nested_geojson_file, use_arrow=use_arrow)
@@ -2358,9 +2339,6 @@ def test_write_memory_driver_required(naturalearth_lowres):
 
 @pytest.mark.parametrize("driver", ["ESRI Shapefile", "OpenFileGDB"])
 def test_write_memory_unsupported_driver(naturalearth_lowres, driver):
-    if driver == "OpenFileGDB" and __gdal_version__ < (3, 6, 0):
-        pytest.skip("OpenFileGDB write support only available for GDAL >= 3.6.0")
-
     df = read_dataframe(naturalearth_lowres)
 
     buffer = BytesIO()
diff --git a/pyogrio/tests/test_raw_io.py b/pyogrio/tests/test_raw_io.py
