Split python-libzim between reader and writer parts

.github/workflows/Tests.yaml

@@ -49,6 +49,30 @@ jobs:
           fail_ci_if_error: true
           token: ${{ secrets.CODECOV_TOKEN }}
 
+  test-reader-only:
+    runs-on: ubuntu-26.04
+    env:
+      LIBZIM_WITHOUT_WRITER: "1"
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Set up Python
+        uses: actions/setup-python@v7
+        with:
+          python-version: "3.14"
+
+      - name: Display Python version
+        run: python -VV
+
+      - name: Install dependencies (and project)
+        run: |
+          pip install -U pip
+          pip install -e .[test,scripts]
+
+      - name: Run the tests
+        run: inv coverage --args "-vvv"
+
   build-docs: # validate that doc can be built
     runs-on: ubuntu-26.04
 

README.md

@@ -33,6 +33,8 @@ Free-threaded CPython is supported: the extension declares itself free-threading
 
 Users on other platforms can install the source distribution (see [Building](#Building) below). 
 
+Writer support is decided when the extension is built, not when it is installed: there is no install-time extra for it. Set `LIBZIM_WITHOUT_WRITER=1` when building against a libzim compiled without writer support; such a build exposes the reader, search, suggestion, illustration and version modules only. Import `libzim.writer` in a `try`/`except ImportError` block to detect writer support at runtime.
+
 
 ## Contributions
 

libzim/__init__.pyi

@@ -4,7 +4,13 @@ from libzim import (
     search,  # pyright: ignore[reportUnusedImport]
     suggestion,  # pyright: ignore[reportUnusedImport]
     version,  # pyright: ignore[reportUnusedImport]
-    writer,  # pyright: ignore[reportUnusedImport]
 )
 
-__all__ = ["illustration", "reader", "search", "suggestion", "version", "writer"]
+__all__ = ["illustration", "reader", "search", "suggestion", "version"]
+
+try:
+    from libzim import writer as writer
+
+    __all__.append("writer")
+except ImportError:
+    pass

libzim/libwrapper.cpp

@@ -28,7 +28,10 @@
 #include <cstdlib>
 #include <iostream>
 #include <zim/blob.h>
+#include <zim/zim_config.h>
+#ifndef LIBZIM_WITHOUT_WRITER
 #include <zim/writer/creator.h>
+#endif
 
 
 ObjWrapper::ObjWrapper(PyObject* obj)
@@ -96,6 +99,7 @@ zim::Blob _callMethodOnObj(PyObject *obj, const std::string& methodName, std::st
   return blob_cy_call_fct(obj, methodName, &error);
 }
 
+#ifndef LIBZIM_WITHOUT_WRITER
 template<>
 std::unique_ptr<zim::writer::ContentProvider>
 _callMethodOnObj(PyObject *obj, const std::string& methodName, std::string& error) {
@@ -119,6 +123,7 @@ zim::writer::IndexData::GeoPosition
 _callMethodOnObj(PyObject *obj, const std::string& methodName, std::string& error) {
   return geoposition_cy_call_fct(obj, methodName, &error);
 }
+#endif // LIBZIM_WITHOUT_WRITER
 
 // This cpp function call a python method on a python object.
 // It checks that we are in a valid state and handle any potential error coming from python.
@@ -136,6 +141,7 @@ Output callMethodOnObj(PyObject* obj, const std::string& methodName) {
 }
 
 
+#ifndef LIBZIM_WITHOUT_WRITER
 /*
 ################################
 #  Content Provider Wrapper    #
@@ -238,6 +244,7 @@ zim::writer::Hints WriterItemWrapper::getHints() const
 {
   return callMethodOnObj<zim::writer::Hints>(m_obj, "get_hints");
 }
+#endif // LIBZIM_WITHOUT_WRITER
 
 zim::Compression comp_from_int(int compValue)
 {

libzim/libwrapper.h

@@ -27,10 +27,14 @@
 #include <zim/entry.h>
 #include <zim/item.h>
 #include <zim/illustration.h>
-#include <zim/writer/item.h>
-#include <zim/writer/contentProvider.h>
 #include <zim/search.h>
 #include <zim/suggestion.h>
+#include <zim/zim_config.h>
+
+#ifndef LIBZIM_WITHOUT_WRITER
+#include <zim/writer/item.h>
+#include <zim/writer/contentProvider.h>
+#endif
 
 struct _object;
 typedef _object PyObject;
@@ -313,6 +317,7 @@ class ObjWrapper
     PyObject* m_obj;
 };
 
+#ifndef LIBZIM_WITHOUT_WRITER
 class WriterItemWrapper : public zim::writer::Item, private ObjWrapper
 {
   public:
@@ -347,6 +352,7 @@ class IndexDataWrapper: public zim::writer::IndexData, private ObjWrapper
     uint32_t getWordCount() const override;
     IndexData::GeoPosition getGeoPosition() const override;
 };
+#endif // LIBZIM_WITHOUT_WRITER
 
 
 // Small helpers