Python – [Errno 2] No such file or directory

I have the following script:

# Run this in the directory containing Glossika GMS-C mp3 files, such
# as for example ENFR-F1-GMS-C-0051.MP3.
# Uses mp3splt which should be available.
# Will REMOVE all existing files of the form ???.mp3 in the current directory,
#   because it uses them for temporary storage, beware.
# Questions, suggestions, etc.:
#   if you're a power user or a programmer, use issues/pull requests on the
#     Gitlab project, https://gitlab.com/avorobey/glossika-tools, or email as
#     you feel appropriate.
#   if you're not, email me at [email protected].
import glob
import os
import re
import subprocess
import sys

files = glob.glob("ENAR-F1-GMS-C-????.mp3")

print "found: ", len(files), " files."

for file in sorted(files):
  print "processing: ", file
  result = re.match("^EN(.{2,4})-..-GMS-C-(dddd).mp3$", file)
  if not result:
    print "unmatched: ", file
    continue
  lang = result.group(1).lower()
  fr = int(result.group(2))
  to = fr+49
  # print "from: ", fr, ", to: ", to
  # removing existing split files
  for f in glob.glob("???.mp3"):
    os.remove(f)
  # running mp3splt
  devnull = open(os.devnull, 'w')
  # Documentations of some important mp3splt options I use and why:
  # -n to not write tags in target files. Makes them easily concatenatable.
  # -x to not write the Xing header in target files. Same reason as -n.
  # -p parameters:
  # min-1.9 to detect 1.9 seconds or more as silence. Normally silence between
  #   sentences as found by mp3splt is just under 3 seconds, but 1.9 also
  #   catches the pause between some standard phrases at the beginning of a
  #   file.
  # th=-64 to set the threshold for detecting silence at -64 DB. The default
  #   value of -48 makes mp3splt miss some of the silences, I don't know why.
  # shots=12 to set the threshold for detecting non-silence. With the default
  #   value of 25 some very short sentences are processed as part of silence.
  # rm=0.1_0 to remove silence between tracks, but leave 0.1 seconds at
  #   the beginning of a track. Without this 0.1, just with "rm", I find that
  #   sometimes mp3splt cuts off a little bit of real sound by mistake.
  #   Comparing with audacity, I see that silence intervals written into
  #   mp3split.log are detected correctly, but for some reason when mp3splt
  #   tries to find the position of the end of the silence interval, it
  #   overshoots by quite a bit. I suspect a deeply placed bug in how mp3splt
  #   processes mpeg frames, and its code is NOT fun to read or debug, so this
  #   is the workaround I found for now.
  status = subprocess.call(["mp3splt", "-n", "-x", "-s",
    "-p", "rm=0.1_0,min=1.9,th=-64,shots=12", "-o", "@N3", file],
    stdout=devnull, stderr=devnull)
  if status != 0:
    sys.exit("bad status running mp3splt")
  split = glob.glob("???.mp3")
  if len(split) != 54:
    sys.exit("surprising number of files: " + str(len(split)) + " for: " + file)
  # use files from 003.mp3 to 052.mp3 inclusive.
  split = sorted(split)[2:52]
  # start at from-1, so for example 1st sentence becomes fr-0000.mp3
  cnt = fr-1
  for f in split:
    name = "{0}-{1:04d}.mp3".format(lang, cnt)
    cnt += 1
    os.rename(f, name)
  print "finished with: ", file
# cleanup
for f in glob.glob("???.mp3"):
  os.remove(f)
os.remove("mp3splt.log")

and get the following error:

found:  20  files.
processing:  ENAR-F1-GMS-C-0001.mp3
Traceback (most recent call last):
  File "glossika-split.py", line 59, in <module>
    stdout=devnull, stderr=devnull)
  File "/usr/local/Cellar/python/2.7.14/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 168, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/local/Cellar/python/2.7.14/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 390, in __init__
    errread, errwrite)
  File "/usr/local/Cellar/python/2.7.14/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1025, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

I am not sure what exactly this might be, as I am not a python programmer but am trying to get this script working. I tried calling it with python script.py as well as python2 script.py. I have the feeling that the stdout is not set properly? But I am not sure. Some help would be really appreciated!