better fallbacks for title and description

pytube/__main__.py

@@ -275,7 +275,11 @@ class YouTube(object):
         :rtype: str
 
         """
-        return self.player_config_args["title"]
+        return self.player_config_args.get("title") or (
+            self.player_config_args.get("player_response", {})
+            .get("videoDetails", {})
+            .get("title")
+        )
 
     @property
     def description(self) -> str:
@@ -284,7 +288,11 @@ class YouTube(object):
         :rtype: str
 
         """
-        return self.vid_descr
+        return self.vid_descr or (
+            self.player_config_args.get("player_response", {})
+            .get("videoDetails", {})
+            .get("shortDescription")
+        )
 
     @property
     def rating(self) -> float:
@@ -306,7 +314,7 @@ class YouTube(object):
         :rtype: str
 
         """
-        return (
+        return self.player_config_args.get("length_seconds") or (
             self.player_config_args.get("player_response", {})
             .get("videoDetails", {})
             .get("lengthSeconds")

pytube/streams.py

@@ -176,20 +176,12 @@ class Stream(object):
         :returns:
             Youtube video title
         """
-        player_config_args = self.player_config_args or {}
-
-        if "title" in player_config_args:
-            return player_config_args["title"]
-
-        details = self.player_config_args.get("player_response", {},).get(
-            "videoDetails", {}
+        return self.player_config_args.get("title") or (
+            self.player_config_args.get("player_response", {})
+            .get("videoDetails", {})
+            .get("title")
         )
 
-        if "title" in details:
-            return details["title"]
-
-        return "Unknown YouTube Video Title"
-
     @property
     def default_filename(self) -> str:
         """Generate filename based on the video title.