improved param parsing and CLI support for choosing languages

youtube_transcript_api/__main__.py

@@ -6,18 +6,57 @@ from pprint import pprint
 
 import logging
 
+import argparse
+
 from ._api import YouTubeTranscriptApi
 
 
+def parse_args(args):
+    parser = argparse.ArgumentParser(
+        description=(
+            'This is an python API which allows you to get the transcripts/subtitles for a given YouTube video. '
+            'It also works for automatically generated subtitles and it does not require a headless browser, like '
+            'other selenium based solutions do!'
+        )
+    )
+    parser.add_argument('video_ids', nargs='*', type=str, help='List of YouTube video IDs.')
+    parser.add_argument(
+        '--languages',
+        nargs='*',
+        default=[],
+        type=str,
+        help=(
+            'A list of language codes in a descending priority. For example, if this is set to "de en" it will first '
+            'try to fetch the german transcript (de) and then fetch the english transcipt (en) if it fails to do so. '
+            'As I can\'t provide a complete list of all working language codes with full certainty, you may have to '
+            'play around with the language codes a bit, to find the one which is working for you!'
+        ),
+    )
+    parser.add_argument(
+        '--json',
+        action='store_const',
+        const=True,
+        default=False,
+        help='If this flag is set the output will be JSON formatted.',
+    )
+
+    return parser.parse_args(args)
+
+
 def main():
     logging.basicConfig()
 
-    if len(sys.argv) <= 1:
-        print('No YouTube video id was found')
-    elif sys.argv[1] == '--json':
-        print(json.dumps(YouTubeTranscriptApi.get_transcripts(sys.argv[2:], continue_after_error=True)[0]))
+    parsed_args = parse_args(sys.argv)
+    transcripts, _ = YouTubeTranscriptApi.get_transcripts(
+        parsed_args.video_ids,
+        languages=parsed_args.languages,
+        continue_after_error=True
+    )
+
+    if parsed_args.json:
+        print(json.dumps(transcripts))
     else:
-        pprint(YouTubeTranscriptApi.get_transcripts(sys.argv[1:], continue_after_error=True)[0])
+        pprint(transcripts)
 
 
 if __name__ == '__main__':