Improve package detection (#253)

If a module has an `__path__` attribute it should be treated as a
package even if it doesn't have any submodules.

Author: gentlegiantJGC

pybind11_stubgen/parser/mixins/parse.py

@@ -107,7 +107,8 @@ def handle_module(
             elif isinstance(obj, TypeVar_):
                 result.type_vars.append(obj)
             elif obj is None:
-                pass
+                if name == "__path__":
+                    result.is_package = True
             else:
                 raise AssertionError()
 

pybind11_stubgen/structs.py

@@ -199,3 +199,4 @@ class Module:
     imports: set[Import] = field_(default_factory=set)
     aliases: list[Alias] = field_(default_factory=list)
     type_vars: list[TypeVar_] = field_(default_factory=list)
+    is_package: bool = field_(default=False)

pybind11_stubgen/writer.py

@@ -16,7 +16,7 @@ def write_module(
     ):
         assert to.exists()
         assert to.is_dir()
-        if module.sub_modules or sub_dir is not None:
+        if module.sub_modules or module.is_package or sub_dir is not None:
             if sub_dir is None:
                 sub_dir = Path(module.name)
             module_dir = to / sub_dir