code: def _data_copier(src_files, dst_files):
      src_files = [
          os.path.normpath(
              os.path.join((os.environ[envvar]), *src_file.split("/"))
          )
          for src_file in src_files
      ]
  
      dst_files = [
          os.path.normpath(
              os.path.join(
                  os.path.dirname(os.path.abspath(os.getcwd())),
                  *dst_file.split("/"),
              )
          )
          for dst_file in dst_files
      ]
  
      if not len(src_files) == len(dst_files):
          raise Exception("The length of src and dst should be same")
  
      for src_dst_file in zip(src_files, dst_files):
          # Note index 0 is the source and index 1 is destination
          if not os.path.isfile(src_dst_file[1]):
              # copy from backup location
              print("Copying file from: ", src_dst_file[0])
              print("Copying file to: ", src_dst_file[1])
              copyfile(src_dst_file[0], src_dst_file[1])
          else:
              print("Reusing cached file", src_dst_file[1])
  
file_path: CNTK/Tests/EndToEndTests/CNTKv2Python/Examples/prepare_test_data.py
imports: import os
  import tarfile
  import zipfile
  from shutil import copyfile
label_desc: Use image node_id 1 for calling a global function with example usage: _data_copier(src_files, dst_files) without return types