old_contents: #!/usr/bin/python
  import glob
  import os
  import subprocess
  import sys
  
  files = sys.argv[1:] if len(sys.argv) > 1 else glob.glob('*')
  for file in files:
      if os.path.isfile(file):
  
          fileWithoutExtension = os.path.splitext(file)[0]
          fileWithMp4Extension = fileWithoutExtension + ".mp4";
          print "Converting " + file + "..."
  
          subprocess.call([
              "ffmpeg",
              "-i", str(file),
              fileWithMp4Extension
          ])
  
new_contents: #!/usr/bin/python3
  import glob
  import os
  import subprocess
  import sys
  
  files = sys.argv[1:] if len(sys.argv) > 1 else glob.glob('*')
  for file in files:
      if os.path.isfile(file):
  
          fileWithoutExtension = os.path.splitext(file)[0]
          fileWithMp4Extension = fileWithoutExtension + ".mp4";
          print("Converting " + file + "...")
  
          subprocess.call([
              "ffmpeg",
              "-i", str(file),
              fileWithMp4Extension
          ])
  
subject: Switch to Python3