fixed bug reported in ISSUE-19

youtube_transcript_api/_api.py

@@ -151,4 +151,5 @@ class _TranscriptParser():
                 'duration': float(xml_element.attrib['dur']),
             }
             for xml_element in ElementTree.fromstring(self.plain_data)
+            if xml_element.text is not None
         ]

youtube_transcript_api/_cli.py

@@ -27,7 +27,7 @@ class YouTubeTranscriptCli():
 
         return '\n\n'.join(
             [str(YouTubeTranscriptApi.CouldNotRetrieveTranscript(video_id)) for video_id in unretrievable_videos]
-            + [json.dumps(transcripts) if parsed_args.json else pprint.pformat(transcripts)]
+            + ([json.dumps(transcripts) if parsed_args.json else pprint.pformat(transcripts)] if transcripts else [])
         )
 
     def _parse_args(self):

youtube_transcript_api/test/assets/transcript.xml.static

@@ -2,5 +2,6 @@
 <transcript>
     <text start="0" dur="1.54">Hey, this is just a test</text>
     <text start="1.54" dur="4.16">this is not the original transcript</text>
+    <text start="5" dur="0.5"></text>
     <text start="5.7" dur="3.239">just something shorter, I made up for testing</text>
 </transcript>