code: def delete_npy(folder):
      case_identifiers = get_case_identifiers(folder)
      npy_files = [
          os.path.join(folder, i + ".npy") for i in case_identifiers
      ]
      npy_files = [i for i in npy_files if os.path.isfile(i)]
      for n in npy_files:
          os.remove(n)
  
file_path: medicaldetectiontoolkit/experiments/lidc_exp/pack_dataset.py
imports: import numpy
  from multiprocessing import Pool
  import os
  import subprocess
label_desc: Use image node_id 4 for calling a global function with example usage: delete_npy(folder) without return types