code: def purge(root="./pretrain_models"):
      r"""Purge all pretrained model files in local file store.
  
      Parameters
      ----------
      root : str, default './pretrain_models'
          Location for keeping the model parameters.
      """
      root = os.path.expanduser(root)
      files = os.listdir(root)
      for f in files:
          if f.endswith(".pth"):
              os.remove(os.path.join(root, f))
  
imports: import os
  import zipfile
  from .files import download, check_sha1
label_desc: Use image node_id 3 for calling a global function with example usage: purge(root) without return types