[reddit:user] implement 'only' option (#8228)

docs/configuration.rst

@@ -5435,6 +5435,16 @@ Note
     but it will not always get the best video quality available.
 
 
+extractor.reddit.user.only
+--------------------------
+Type
+    ``bool``
+Default
+    ``trur``
+Description
+    Only process and return posts from the user specified in the input URL.
+
+
 extractor.redgifs.format
 ------------------------
 Type

docs/gallery-dl.conf

@@ -707,7 +707,11 @@
             "previews"    : true,
             "recursion"   : 0,
             "selftext"    : null,
-            "videos"      : "dash"
+            "videos"      : "dash",
+
+            "user": {
+                "only": true
+            }
         },
         "redgifs":
         {

gallery_dl/extractor/reddit.py

@@ -317,8 +317,23 @@ class RedditUserExtractor(RedditExtractor):
 
         submissions = self.api.submissions_user(
             user["name"], text.parse_query(qs))
+        if self.config("only", True):
+            submissions = self._only(submissions, user)
         return submissions
 
+    def _only(self, submissions, user):
+        uid = "t2_" + user["id"]
+        for submission, comments in submissions:
+            if submission and submission.get("author_fullname") != uid:
+                submission = None
+            comments = [
+                comment
+                for comment in (comments or ())
+                if comment.get("author_fullname") == uid
+            ]
+            if submission or comments:
+                yield submission, comments
+
 
 class RedditSubmissionExtractor(RedditExtractor):
     """Extractor for URLs from a submission on reddit.com"""