Extract script language extension classes from _pythonscript into godot._lang

Author: touilleMan

src/_pythonscript_editor.pxi

@@ -1,10 +1,16 @@
+# TODO: now that the gdptrs are located in `libpythonscript.so`, doing a `import godot`
+# from a python interpreter cause a `ImportError: libpythonscript.so: cannot open shared object file: No such file or directory`
+# when doing `from godot.builtins import *`. We should change the sanity check accordingly...
+
 # Start with a sanity check to ensure the loading is done from Godot-Python
 # (and not from a regular Python interpreter which would lead to a segfault).
 # The idea is we should have the following loading order:
-# godot binary -> libpythonscript.so -> _pythonscript.so -> godot/__init__.py
+# godot binary -> libpythonscript.so -> godot/__init__.py
 import sys
 
-if "_pythonscript" not in sys.modules:
+if (
+    sys.argv[0] == ""
+):  # `sys.argv` is configured later on by `godot._lang._pythonscript_initialize()`
     raise ImportError(
         "Cannot initialize godot module given Godot GDExtension API not available.\n"
         "This is most likely because you are running code from a regular Python interpreter"
@@ -13,7 +19,7 @@
     )
 del sys
 
-from godot._version import __version__
+from godot._version import __version__  # noqa: E402, F401
 
 # from godot.tags import (
 #     MethodRPCMode,
@@ -32,7 +38,7 @@
 #     export,
 #     exposed,
 # )
-from godot.builtins import *
+from godot.builtins import *  # noqa: E402, F403
 
 # from godot.classes import _load_singleton, _load_class