[postprocessor:metadata] first implementation (#135)

gallery_dl/option.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2017-2018 Mike Fährmann
+# Copyright 2017-2019 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
@@ -268,6 +268,12 @@ def build_parser():
         dest="postprocessors", const=({"name": "ugoira"},),
         help="Convert Pixiv Ugoira to WebM (requires FFmpeg)",
     )
+    postprocessor.add_argument(
+        "--write-metadata",
+        action=ConfigConstAction, nargs=0,
+        dest="postprocessors", const=({"name": "metadata"},),
+        help="Write metadata to separate JSON files",
+    )
 
     parser.add_argument(
         "urls",

gallery_dl/postprocessor/metadata.py

@@ -0,0 +1,33 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 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.
+
+"""Write metadata to JSON files"""
+
+from .common import PostProcessor
+import json
+
+
+class MetadataPP(PostProcessor):
+
+    def __init__(self, pathfmt, options):
+        PostProcessor.__init__(self)
+        self.indent = options.get("indent", 4)
+        self.ascii = options.get("ascii", False)
+
+    def run(self, pathfmt):
+        with open(pathfmt.realpath + ".json", "w") as file:
+            json.dump(
+                pathfmt.keywords,
+                file,
+                sort_keys=True,
+                indent=self.indent,
+                ensure_ascii=self.ascii,
+            )
+
+
+__postprocessor__ = MetadataPP