updated README, added test_deprecated

README.md

@@ -138,17 +138,17 @@ Conversely, if you only want to see the DASH streams (also referred to as "adapt
   <Stream: itag="251" mime_type="audio/webm" abr="160kbps" acodec="opus">]
 ```
 
+### Playlists
+
 You can also download a complete Youtube playlist:
 
 ```python
 >>> from pytube import Playlist
->>> pl = Playlist("https://www.youtube.com/watch?v=Edpy1szoG80&list=PL153hDY-y1E00uQtCVCVC8xJ25TYX8yPU")
->>> pl.download_all()
->>> # or if you want to download in a specific directory
->>> pl.download_all('/path/to/directory/')
+>>> playlist = Playlist("https://www.youtube.com/playlist?list=PLynhp4cZEpTbRs_PYISQ8v_uwO0_mDg_X")
+>>> for video in playlist.videos:
+>>> 	video.streams.get_highest_resolution().download()
 ```
-This will download the highest progressive stream available (generally 720p) from the given playlist. Later more options would be given for user's flexibility
-to choose video resolution.
+This will download the highest progressive stream available (generally 720p) from the given playlist.
 
 ### Filtering
 

pytube/helpers.py

@@ -1,7 +1,6 @@
 # -*- coding: utf-8 -*-
 """Various helper functions implemented by pytube."""
 import functools
-import inspect
 import logging
 import pprint
 import re
@@ -112,7 +111,7 @@ def cache(func: Callable[..., GenericType]) -> GenericType:
     return functools.lru_cache()(func)  # type: ignore
 
 
-def deprecated(reason):
+def deprecated(reason: str) -> Callable:
     """
     This is a decorator which can be used to mark functions
     as deprecated. It will result in a warning being emitted
@@ -120,16 +119,13 @@ def deprecated(reason):
     """
 
     def decorator(func1):
-        if inspect.isclass(func1):
-            fmt1 = "Call to deprecated class {name} ({reason})."
-        else:
-            fmt1 = "Call to deprecated function {name} ({reason})."
+        message = "Call to deprecated function {name} ({reason})."
 
         @functools.wraps(func1)
         def new_func1(*args, **kwargs):
             warnings.simplefilter("always", DeprecationWarning)
             warnings.warn(
-                fmt1.format(name=func1.__name__, reason=reason),
+                message.format(name=func1.__name__, reason=reason),
                 category=DeprecationWarning,
                 stacklevel=2,
             )

pytube/query.py

@@ -273,6 +273,22 @@ class StreamQuery:
             .last()
         )
 
+    def get_highest_resolution(self) -> Optional[Stream]:
+        """Get highest resolution stream that is a progressive video.
+
+        :rtype: :class:`Stream <Stream>` or None
+        :returns:
+            The :class:`Stream <Stream>` matching the given itag or None if
+            not found.
+
+        """
+        return (
+            self.filter(progressive=True)
+            .order_by("resolution")
+            .asc()
+            .last()
+        )
+
     def first(self) -> Optional[Stream]:
         """Get the first :class:`Stream <Stream>` in the results.