code: def valid_textfile(filedir):
      # Generate and return a valid temporary file.
      fd, path = mkstemp(
          suffix=".txt", prefix="dstmp_", dir=filedir, text=True
      )
      os.close(fd)
      return path
  
imports: import os
  import pytest
  from tempfile import mkdtemp, mkstemp, NamedTemporaryFile
  from shutil import rmtree
  import numpy.lib._datasource
  from numpy.testing import assert_, assert_equal, assert_raises
  import urllib.request
  from urllib.parse import urlparse
  from urllib.error import URLError
label_desc: Use image node_id 4 for calling a global function with example usage: valid_textfile(filedir) and returns: path