python-mapnik_data_path.patch

From 221d4fb5840b8544e3948947f9c39208b669a5b5 Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Wed, 30 Sep 2026 18:39:08 +0000
Subject: [PATCH] Add local paths for proj and gdal

---
 packaging/mapnik/__init__.py | 13 ++++++++-----
 setup.py                     |  3 ++-
 src/mapnik_data_paths.cpp    | 22 ++++++++++++++++++++++
 src/mapnik_python.cpp        |  2 ++
 4 files changed, 34 insertions(+), 6 deletions(-)
 create mode 100644 src/mapnik_data_paths.cpp

diff --git a/packaging/mapnik/__init__.py b/packaging/mapnik/__init__.py
index 64cea4f..2b06c58 100644
--- a/packaging/mapnik/__init__.py
+++ b/packaging/mapnik/__init__.py
@@ -52,11 +52,6 @@ if os.path.exists(libpath):
     ctypes.cdll.LoadLibrary(os.path.join(libpath, libgdalpath))
 
 
-
-localpath = os.path.dirname(os.path.abspath( __file__ ))
-os.environ.setdefault("PROJ_DATA", os.path.join(localpath, "proj"))
-os.environ.setdefault("GDAL_DATA", os.path.join(localpath, "gdal"))
-
 def bootstrap_env():
     """
     If an optional settings file exists, inherit its
@@ -82,6 +77,14 @@ bootstrap_env()
 
 from ._mapnik import *
 
+localpath = os.path.dirname(os.path.abspath( __file__ ))
+_bundled_proj_dir = os.path.join(localpath, "proj")
+_bundled_gdal_dir = os.path.join(localpath, "gdal")
+set_data_paths(
+    _bundled_proj_dir if os.path.isdir(_bundled_proj_dir) else "",
+    _bundled_gdal_dir if os.path.isdir(_bundled_gdal_dir) else "",
+)
+
 def Shapefile(**keywords):
     """Create a Shapefile Datasource.
 
diff --git a/setup.py b/setup.py
index 780ba70..b58ab9d 100755
--- a/setup.py
+++ b/setup.py
@@ -106,7 +106,8 @@ ext_modules = [
                "src/mapnik_dot_symbolizer.cpp",
                "src/mapnik_building_symbolizer.cpp",
                "src/mapnik_shield_symbolizer.cpp",
-               "src/mapnik_group_symbolizer.cpp"
+               "src/mapnik_group_symbolizer.cpp",
+               "src/mapnik_data_paths.cpp"
           ],
           extra_compile_args=extra_comp_args,
           extra_link_args=linkflags,
diff --git a/src/mapnik_data_paths.cpp b/src/mapnik_data_paths.cpp
new file mode 100644
index 0000000..d0f172e
--- /dev/null
+++ b/src/mapnik_data_paths.cpp
@@ -0,0 +1,22 @@
+#include <mapnik/data_paths.hpp>
+
+#include <pybind11/pybind11.h>
+
+#include <string>
+
+namespace py = pybind11;
+
+void export_data_paths(py::module& m)
+{
+    m.def("set_data_paths",
+          &mapnik::set_data_paths,
+          py::arg("proj_dir") = "",
+          py::arg("gdal_dir") = "",
+          "Configure the PROJ and GDAL data directories used by mapnik without\n"
+          "touching the process environment. An empty string leaves the\n"
+          "corresponding library using its own default lookup.\n");
+
+    m.def("proj_data_dir", &mapnik::proj_data_dir, "Directory configured for PROJ data ('' if unset).\n");
+
+    m.def("gdal_data_dir", &mapnik::gdal_data_dir, "Directory configured for GDAL data ('' if unset).\n");
+}
diff --git a/src/mapnik_python.cpp b/src/mapnik_python.cpp
index 81222e9..7a1636d 100644
--- a/src/mapnik_python.cpp
+++ b/src/mapnik_python.cpp
@@ -581,6 +581,7 @@ void export_dot_symbolizer(py::module const&);
 void export_shield_symbolizer(py::module const&);
 void export_group_symbolizer(py::module const&);
 void export_building_symbolizer(py::module const&);
+void export_data_paths(py::module&); // non-const because of m.def(..)
 
 using mapnik::load_map;
 using mapnik::load_map_string;
@@ -636,6 +637,7 @@ PYBIND11_MODULE(_mapnik, m) {
     export_shield_symbolizer(m);
     export_group_symbolizer(m);
     export_building_symbolizer(m);
+    export_data_paths(m);
     // exceptions
     py::register_exception<mapnik::value_error>(m, "PyExc_MapnikValueError", PyExc_ValueError);
     //
-- 
2.56.0