[Python] Use cppyy.types module instead of private cppyy._backend

Do what @wlav suggested in
#20287 (comment).

Author: guitargeek

bindings/pyroot/pythonizations/python/ROOT/__init__.py

@@ -32,6 +32,7 @@
 from . import _asan
 
 import cppyy
+import cppyy.types
 
 # Build cache of commonly used python strings (the cache is python intern, so
 # all strings are shared python-wide, not just in PyROOT).
@@ -111,7 +112,7 @@ def _can_be_module(obj) -> bool:
 import types
 
 
-def _lookup_root_module(fullname: str) -> Optional[Union[types.ModuleType, cppyy._backend.CPPScope]]:
+def _lookup_root_module(fullname: str) -> Optional[Union[types.ModuleType, cppyy.types.Scope]]:
     """
     Recursively looks up attributes of the ROOT facade, using a full module
     name, and return it if it can be used as a ROOT submodule. This is the case

bindings/pyroot/pythonizations/python/ROOT/_pythonization/_rdf_pyz.py

@@ -321,11 +321,12 @@ def _get_cpp_signature(func, rdf, cols):
     Gets the C++ signature of a cppyy callable.
     """
     import cppyy
+    import cppyy.types
 
-    if isinstance(func, cppyy._backend.TemplateProxy):
+    if isinstance(func, cppyy.types.Template):
         func = get_cpp_overload_from_templ_proxy(func, get_column_types(rdf, cols))
 
-    if not isinstance(func, cppyy._backend.CPPOverload):
+    if not isinstance(func, cppyy.types.Function):
         raise TypeError(f"Expected a cppyy callable, got {type(func).__name__}")
 
     overload_types = func.func_overloads_types
@@ -338,8 +339,9 @@ def _to_std_function(func, rdf, cols):
     Converts a cppyy callable to std::function.
     """
     import cppyy
+    import cppyy.types
 
-    if not isinstance(func, cppyy._backend.CPPOverload) and not isinstance(func, cppyy._backend.TemplateProxy):
+    if not isinstance(func, cppyy.types.Function) and not isinstance(func, cppyy.types.Template):
         raise TypeError(f"Expected a cppyy callable, got {type(func).__name__}")
 
     signature = _get_cpp_signature(func, rdf, cols)
@@ -373,10 +375,11 @@ def _handle_cpp_callables(func, original_template, *args, rdf=None, cols=None):
     """
 
     import cppyy
+    import cppyy.types
 
-    is_cpp_functor = lambda: isinstance(getattr(func, "__call__", None), cppyy._backend.CPPOverload)  # noqa E731
+    is_cpp_functor = lambda: isinstance(getattr(func, "__call__", None), cppyy.types.Function)  # noqa E731
 
-    is_std_function = lambda: isinstance(getattr(func, "target_type", None), cppyy._backend.CPPOverload)  # noqa E731
+    is_std_function = lambda: isinstance(getattr(func, "target_type", None), cppyy.types.Function)  # noqa E731
 
     # handle free functions
     if callable(func) and not is_cpp_functor() and not is_std_function():

bindings/pyroot/pythonizations/python/ROOT/_pythonization/_roofit/_utils.py

@@ -24,10 +24,11 @@ def getter(k, v):
         # We have to use ROOT here and not cppy.gbl, because the RooFit namespace is pythonized itself.
         import ROOT
         import cppyy
+        import cppyy.types
 
         func = getattr(ROOT.RooFit, k)
 
-        if isinstance(func, cppyy._backend.CPPOverload):
+        if isinstance(func, cppyy.types.Function):
             # Pythonization for functions that don't pass any RooCmdArgs like ShiftToZero() and MoveToBack(). For Eg,
             # Default bindings: pdf.plotOn(frame, ROOT.RooFit.MoveToBack())
             # With pythonizations: pdf.plotOn(frame, MoveToBack=True)

bindings/pyroot/pythonizations/python/ROOT/_pythonization/_ttree.py

@@ -254,11 +254,12 @@ def _SetBranchAddress(self, bname, addr, *args, **kwargs):
     ```
     """
     import cppyy
+    import cppyy.types
 
     branch = self.GetBranch(bname)
 
     # Pythonization for cppyy proxies (of type CPPInstance)
-    if isinstance(addr, cppyy._backend.CPPInstance):
+    if isinstance(addr, cppyy.types.Instance):
         addr = _pythonize_branch_addr(branch, addr)
 
     # Figure out data_type in case addr is a numpy.ndarray or array.array

roottest/python/basic/PyROOT_datatypetest.py

@@ -37,7 +37,7 @@ def setup_class(cls):
         cls.datatypes = cppyy.load_reflection_info(cls.test_dct)
         cls.N = cppyy.gbl.N
         # In new Cppyy, nullptr can't be found in gbl.
-        cls.nullptr = cppyy._backend.nullptr
+        cls.nullptr = cppyy.nullptr
 
     def test01_load_reflection_cache(self):
         """Loading reflection info twice should result in the same object"""

roottest/python/basic/PyROOT_datatypetest_numpy.py

@@ -37,7 +37,7 @@ def setup_class(cls):
         cls.datatypes = cppyy.load_reflection_info(cls.test_dct)
         cls.N = cppyy.gbl.N
         # In new Cppyy, nullptr can't be found in gbl.
-        cls.nullptr = cppyy._backend.nullptr
+        cls.nullptr = cppyy.nullptr
 
     def test01_buffer_to_numpy(self):
         """Wrap buffer with NumPy array"""