made interaction with user more friendly

coub-dl.py

@@ -1,6 +1,6 @@
-from subprocess import call, Popen, PIPE, check_output
+from subprocess import call, Popen, PIPE, check_output, DEVNULL
 from os import listdir, remove
-from os.path import splitext
+from os.path import splitext, exists
 from re import match
 from sys import argv
 from enum import Enum
@@ -32,11 +32,17 @@ def getDuration(ffprobe_output):
     return duration
 
 def downloadStreams():
+    print('Downloading audio stream... ', end='', flush=True)
     call(('/usr/bin/env', 'youtube-dl', '--extract-audio',
                                         '--output', '{}.%(ext)s'.format(FILES[Stream.AUDIO]),
-                                        URL))
+                                        URL),
+         stdout=DEVNULL, stderr=DEVNULL)
+    print('Done!')
+    print('Downloading video stream... ', end='', flush=True)
     call(('/usr/bin/env', 'youtube-dl', '--output', '{}.%(ext)s'.format(FILES[Stream.VIDEO]),
-                                        URL))
+                                        URL),
+         stdout=DEVNULL, stderr=DEVNULL)
+    print('Done!')
 
 def readExtensions():
     for file in listdir():
@@ -44,6 +50,28 @@ def readExtensions():
             if match('^{}.*'.format(FILES[filename]), file):
                 FILES[filename] = file
 
+def yes_no_question(question, default):
+    valid = {"yes": True, "y": True, "ye": True,
+             "no": False, "n": False}
+    if default is None:
+        prompt = " [y/n] "
+    elif default == "yes":
+        prompt = " [Y/n] "
+    elif default == "no":
+        prompt = " [y/N] "
+    else:
+        raise ValueError("Invalid default answer: {}!".format(default))
+
+    while True:
+        print(question + prompt)
+        choice = input().lower()
+        if default is not None and choice == '':
+            return valid[default]
+        elif choice in valid:
+            return valid[choice]
+        else:
+            print("Please respond with 'yes'(y) or 'no'(n)!")
+
 
 FILES = {Stream.AUDIO: 'audio', Stream.VIDEO: 'video',
          File.LIST: 'list.txt', File.LOOP: 'loop', File.OUTPUT: 'output.mp4'}
@@ -51,6 +79,19 @@ OUTPUT_KEYS = [File.OUTPUT]
 URL = argv[1] if len(argv) > 0 else ''  # youtube-dl error message will be shown if ''
 
 
+# fetch video title
+FILES[File.OUTPUT] = check_output(('/usr/bin/env', 'youtube-dl', '--get-title', argv[1])).decode('utf-8').strip() + '.mp4'
+
+# ask what to do if output exists
+if exists(FILES[File.OUTPUT]):
+    answer = yes_no_question('A file named "{}" already exists! Overwrite?'.format(FILES[File.OUTPUT]), default='no')
+    if not answer:
+        print('Exiting!')
+        exit()
+    else:
+        remove(FILES[File.OUTPUT])
+
+# download streams and update FILE dict with extensions
 downloadStreams()
 readExtensions()
 
@@ -74,16 +115,18 @@ with open(FILES[File.LIST], 'w') as f:
     for i in range(timesLoop):
         print("file '{}'".format(shorterFile), file=f)
 
-
-# fetch video title
-FILES[File.OUTPUT] = check_output(('/usr/bin/env', 'youtube-dl', '--get-title', argv[1])).decode('utf-8').strip() + '.mp4'
-
 # loop & mux
-call(('/usr/bin/env', 'ffmpeg', '-f', 'concat', '-i', FILES[File.LIST], '-c', 'copy', FILES[File.LOOP]))
+print('Looping shorter stream... ', end='', flush=True)
+call(('/usr/bin/env', 'ffmpeg', '-f', 'concat', '-i', FILES[File.LIST], '-c', 'copy', FILES[File.LOOP]),
+     stdout=DEVNULL, stderr=DEVNULL)
+print('Done!')
+print('Muxing streams... ', end='', flush=True)
 call(('/usr/bin/env', 'ffmpeg', '-i', FILES[File.LOOP],
                                 '-i', FILES[Stream.AUDIO],
                                 '-map', '0', '-map', '1',
-                                '-c', 'copy', FILES[File.OUTPUT]))
+                                '-c', 'copy', FILES[File.OUTPUT]),
+     stdout=DEVNULL, stderr=DEVNULL)
+print('Done!')
 
 # cleanup
 for key in FILES: