Feature: Blender hook to execute python scripts at launch

openpype/hosts/blender/hooks/pre_add_run_python_script_arg.py

@@ -0,0 +1,61 @@
+from pathlib import Path
+
+from openpype.lib import PreLaunchHook
+from openpype.settings.lib import get_project_settings
+
+
+class AddPythonScriptToLaunchArgs(PreLaunchHook):
+    """Add python script to be executed before Blender launch."""
+
+    # Append after file argument
+    order = 15
+    app_groups = [
+        "blender",
+    ]
+
+    def execute(self):
+        # Check enabled in settings
+        project_name = self.data["project_name"]
+        project_settings = get_project_settings(project_name)
+        host_name = self.application.host_name
+        host_settings = project_settings.get(host_name)
+        if not host_settings:
+            self.log.info(f"""Host "{host_name}" doesn\'t have settings""")
+            return None
+
+        # Add path to workfile to arguments
+        for python_script_path in self.launch_context.data.get(
+            "python_scripts", []
+        ):
+            self.log.info(
+                f"Adding python script {python_script_path} to launch"
+            )
+            # Test script path exists
+            if not Path(python_script_path).exists():
+                raise ValueError(
+                    f"Python script {python_script_path} doesn't exist."
+                )
+
+            if "--" in self.launch_context.launch_args:
+                # Insert before separator
+                separator_index = self.launch_context.launch_args.index("--")
+                self.launch_context.launch_args.insert(
+                    separator_index,
+                    "-P",
+                )
+                self.launch_context.launch_args.insert(
+                    separator_index + 1,
+                    Path(python_script_path).as_posix(),
+                )
+            else:
+                self.launch_context.launch_args.extend(
+                    ["-P", Path(python_script_path).as_posix()]
+                )
+
+        # Ensure separator
+        if "--" not in self.launch_context.launch_args:
+            self.launch_context.launch_args.append("--")
+
+        self.launch_context.launch_args.extend(
+            [*self.launch_context.data.get("script_args", [])]
+        )