Pass %(ext)s when filename is provided on command line

dlaudio.py

@@ -3,22 +3,35 @@
 
 Dependencies:
 =============
+
 * youtube-dl
 """
 
 import argparse
-import pathlib
+from pathlib import Path
-import shutil
 import subprocess
 
 # =========== Constants ==========
-YOUTUBE_DL_BIN = shutil.which("youtube-dl")
+YOUTUBE_DL_BIN = "/usr/bin/youtube-dl"
-DEFAULT_FILENAME = f"{pathlib.Path.home()}/Music/%(title)s.%(ext)s"
+DEFAULT_FILENAME = f"{Path.home() / 'Music'}/%(title)s.%(ext)s"
+DEFAULT_YOUTUBE_DL_OPTS = (
+    "--no-part",
+    "--audio-quality=0",
+    "--no-continue",
+    "--extract-audio",
+)
 
-# ========== Error Codes ==========
+# ----- Error Codes -----
 E_NOURLS = 2
 
-# ========== Main Script ==========
+
+# ========== Functions ==========
+def parse_cmdline_arguments(**kwargs):
+    """Parse command line arguments passed to the script.
+        All kwargs are passed to ArgumentParser.parse_args().
+
+    :rtype: argparse.Namespace object
+    """
     parser = argparse.ArgumentParser()
     parser.add_argument("-b", "--batchfile", help="provide the links from a text file")
     parser.add_argument(
@@ -28,20 +41,24 @@ parser.add_argument(
         "-n", "--filename", type=str, help="downloaded filename (without extension)"
     )
     parser.add_argument("urls", nargs="*", help="video URLs")
-args = parser.parse_args()
+
+    return parser.parse_args()
+
+
+# ========== Main Script ==========
+if __name__ == "__main__":
+    args = parse_cmdline_arguments()
 
     dl_opts = [
         YOUTUBE_DL_BIN,
-    "--no-part",
+        *DEFAULT_YOUTUBE_DL_OPTS,
-    "--no-continue",
-    "--extract-audio",
         f"--audio-format={args.format}",
     ]
 
     # filename handling
     # if -b is used, DEFAULT_FILENAME must take precedence
     if args.filename is not None and args.batchfile is None:
-    dl_opts.append(f"--output={args.filename}")
+        dl_opts.append(f"--output={Path.home() / 'Music' / args.filename}.%(ext)s")
     else:
         dl_opts.append(f"--output={DEFAULT_FILENAME}")