[extractor] Generalize getcomments implementation

yt_dlp/extractor/common.py

@@ -3502,6 +3502,32 @@ class InfoExtractor(object):
     def _get_subtitles(self, *args, **kwargs):
         raise NotImplementedError('This method must be implemented by subclasses')
 
+    def extract_comments(self, *args, **kwargs):
+        if not self.get_param('getcomments'):
+            return None
+        generator = self._get_comments(*args, **kwargs)
+
+        def extractor():
+            comments = []
+            try:
+                while True:
+                    comments.append(next(generator))
+            except KeyboardInterrupt:
+                interrupted = True
+                self.to_screen('Interrupted by user')
+            except StopIteration:
+                interrupted = False
+            comment_count = len(comments)
+            self.to_screen(f'Extracted {comment_count} comments')
+            return {
+                'comments': comments,
+                'comment_count': None if interrupted else comment_count
+            }
+        return extractor
+
+    def _get_comments(self, *args, **kwargs):
+        raise NotImplementedError('This method must be implemented by subclasses')
+
     @staticmethod
     def _merge_subtitle_items(subtitle_list1, subtitle_list2):
         """ Merge subtitle items for one language. Items with duplicated URLs