ENH: add get_gdal_data_path to query GDAL data directory (#160)

CHANGES.md

@@ -2,6 +2,11 @@
 
 ## O.4.2
 
+### Improvements
+
+-   new `get_gdal_data_path()` utility funtion to check the path of the data
+    directory detected by GDAL (#160)
+
 ### Bug fixes
 
 -   register GDAL drivers during initial import of pyogrio (#145)

pyogrio/__init__.py

@@ -5,6 +5,7 @@
     read_info,
     set_gdal_config_options,
     get_gdal_config_option,
+    get_gdal_data_path,
     __gdal_version__,
     __gdal_version_string__,
     __gdal_geos_version__,
@@ -23,6 +24,7 @@
     "read_info",
     "set_gdal_config_options",
     "get_gdal_config_option",
+    "get_gdal_data_path",
     "read_dataframe",
     "write_dataframe",
     "__gdal_version__",

pyogrio/_ogr.pyx

@@ -183,6 +183,16 @@ def has_gdal_data():
     return False
 
 
+def get_gdal_data_path():
+    """
+    Get the path to the directory GDAL uses to read data files. 
+    """
+    cdef const char *path_c = CPLFindFile("gdal", "header.dxf")
+    if path_c != NULL:
+        return get_string(path_c).rstrip("header.dxf")
+    return None
+
+
 def has_proj_data():
     """Verify that PROJ library data files are correctly found.
 

pyogrio/core.py

@@ -10,6 +10,7 @@
         ogr_list_drivers,
         set_gdal_config_options as _set_gdal_config_options,
         get_gdal_config_option as _get_gdal_config_option,
+        get_gdal_data_path as _get_gdal_data_path,
         init_gdal_data as _init_gdal_data,
         init_proj_data as _init_proj_data,
         remove_virtual_file,
@@ -221,3 +222,13 @@ def get_gdal_config_option(name):
     """
 
     return _get_gdal_config_option(name)
+
+
+def get_gdal_data_path():
+    """Get the path to the directory GDAL uses to read data files.
+
+    Returns
+    -------
+    str, or None if data directory was not found
+    """
+    return _get_gdal_data_path()

pyogrio/tests/test_core.py

@@ -10,6 +10,7 @@
     read_info,
     set_gdal_config_options,
     get_gdal_config_option,
+    get_gdal_data_path,
 )
 
 from pyogrio._env import GDALEnv
@@ -32,6 +33,12 @@ def test_proj_data():
     assert has_proj_data()
 
 
+def test_get_gdal_data_path():
+    # test will fail if the function returns None, which means that GDAL
+    # cannot find data files, indicating an installation error
+    assert isinstance(get_gdal_data_path(), str)
+
+
 def test_gdal_geos_version():
     assert __gdal_geos_version__ is None or isinstance(__gdal_geos_version__, tuple)