Introducing filesize returned in kb, mb and gb (#1364)

* Enable inbuilt conversion(with rounding) to KB, MB and GB for the filesize attribute

* return kb, mb, gb as floats rounded up to 3 significant figures

* updating filesize function with appropriate naming conventions

pytube/streams.py

@@ -8,6 +8,8 @@ separately).
 """
 import logging
 import os
+from math import ceil
+
 from datetime import datetime
 from typing import BinaryIO, Dict, Optional, Tuple
 from urllib.error import HTTPError
@@ -61,6 +63,15 @@ class Stream:
 
         # filesize in bytes
         self._filesize: Optional[int] = int(stream.get('contentLength', 0))
+        
+        # filesize in kilobytes
+        self._filesize_kb: Optional[float] = float(ceil(stream.get('contentLength', 0) / 1024 * 1000) / 1000)
+        
+        # filesize in megabytes
+        self._filesize_mb: Optional[float] = float(ceil(stream.get('contentLength', 0) / 1024 / 1024 * 1000) / 1000)
+        
+        # filesize in gigabytes(fingers crossed we don't need terabytes going forward though)
+        self._filesize_gb: Optional[float] = float(ceil(stream.get('contentLength', 0) / 1024 / 1024 / 1024 * 1000) / 1000)
 
         # Additional information about the stream format, such as resolution,
         # frame rate, and whether the stream is live (HLS) or 3D.
@@ -149,7 +160,58 @@ class Stream:
                     raise
                 self._filesize = request.seq_filesize(self.url)
         return self._filesize
+    
+    @property
+    def filesizekb(self) -> float:
+        """File size of the media stream in bytes.
+
+        :rtype: float
+        :returns:
+            Rounded filesize (in kilobytes) of the stream.
+        """
+        if self._filesize_kb == 0:
+            try:
+                self._filesize_kb = float(ceil(request.filesize(self.url)/1024 * 1000) / 1000)
+            except HTTPError as e:
+                if e.code != 404:
+                    raise
+                self._filesize_kb = float(ceil(request.seq_filesize(self.url)/1024 * 1000) / 1000)
+        return self._filesize_kb
+    
+    @property
+    def filesizemb(self) -> float:
+        """File size of the media stream in bytes.
+
+        :rtype: float
+        :returns:
+            Rounded filesize (in megabytes) of the stream.
+        """
+        if self._filesize_mb == 0:
+            try:
+                self._filesize_mb = float(ceil(request.filesize(self.url)/1024/1024 * 1000) / 1000)
+            except HTTPError as e:
+                if e.code != 404:
+                    raise
+                self._filesize_mb = float(ceil(request.seq_filesize(self.url)/1024/1024 * 1000) / 1000)
+        return self._filesize_mb
+
+    @property
+    def filesizegb(self) -> float:
+        """File size of the media stream in bytes.
 
+        :rtype: float
+        :returns:
+            Rounded filesize (in gigabytes) of the stream.
+        """
+        if self._filesize_gb == 0:
+            try:
+                self._filesize_gb = float(ceil(request.filesize(self.url)/1024/1024/1024 * 1000) / 1000)
+            except HTTPError as e:
+                if e.code != 404:
+                    raise
+                self._filesize_gb = float(ceil(request.seq_filesize(self.url)/1024/1024/1024 * 1000) / 1000)
+        return self._filesize_gb
+    
     @property
     def title(self) -> str:
         """Get title of video

tests/test_streams.py

@@ -29,7 +29,15 @@ def test_stream_to_buffer(mock_request, cipher_signature):
 
 def test_filesize(cipher_signature):
     assert cipher_signature.streams[0].filesize == 3399554
+    
+def test_filesize_kb(cipher_signature):
+    assert cipher_signature.streams[0].filesize_kb == float(3319.877)
 
+def test_filesize_mb(cipher_signature):
+    assert cipher_signature.streams[0].filesize_mb == float(3.243)
+
+def test_filesize_gb(cipher_signature):
+    assert cipher_signature.streams[0].filesize_gb == float(0.004)
 
 def test_filesize_approx(cipher_signature):
     stream = cipher_signature.streams[0]