[instagram] add 'order-files' option (#4017, #3993)

docs/configuration.rst

@@ -1817,6 +1817,23 @@ Description
     It is possible to use ``"all"`` instead of listing all values separately.
 
 
+extractor.instagram.order-files
+-------------------------------
+Type
+    ``string``
+Default
+    ``"asc"``
+Description
+    Controls the order in which files of each post are returned.
+
+    * ``"asc"``: Same order as displayed in a post
+    * ``"desc"``: Reverse order as displayed in a post
+    * ``"reverse"``: Same as ``"desc"``
+
+    Note: This option does *not* affect ``{num}``.
+    To enumerate files in reverse order, use ``count - num + 1``.
+
+
 extractor.instagram.previews
 ----------------------------
 Type

gallery_dl/extractor/instagram.py

@@ -55,6 +55,9 @@ class InstagramExtractor(Extractor):
         previews = self.config("previews", False)
         video_headers = {"User-Agent": "Mozilla/5.0"}
 
+        order = self.config("order-files")
+        reverse = order[0] in ("r", "d") if order else False
+
         for post in self.posts():
 
             if "__typename" in post:
@@ -71,6 +74,8 @@ class InstagramExtractor(Extractor):
 
             if "date" in post:
                 del post["date"]
+            if reverse:
+                files.reverse()
 
             for file in files:
                 file.update(post)