[pp:directory] add 'directory' post processor (#7432)

gallery_dl/postprocessor/__init__.py

@@ -11,6 +11,7 @@
 modules = [
     "classify",
     "compare",
+    "directory",
     "exec",
     "hash",
     "metadata",

gallery_dl/postprocessor/directory.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2025 Mike Fährmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+"""Trigger directory format string evaluation"""
+
+from .common import PostProcessor
+
+
+class DirectoryPP(PostProcessor):
+
+    def __init__(self, job, options):
+        PostProcessor.__init__(self, job)
+
+        events = options.get("event")
+        if events is None:
+            events = ("prepare",)
+        elif isinstance(events, str):
+            events = events.split(",")
+        job.register_hooks({event: self.run for event in events}, options)
+
+    def run(self, pathfmt):
+        pathfmt.set_directory(pathfmt.kwdict)
+
+
+__postprocessor__ = DirectoryPP