code: def clean_dir(root):
      '''remove .* and _* files and directories under root'''
      for x in root.walkdirs('.*', errors='ignore'):
          x.rmtree()
      for x in root.walkdirs('_*', errors='ignore'):
          x.rmtree()
  
      for x in root.walkfiles('.*', errors='ignore'):
          x.remove()
      for x in root.walkfiles('_*', errors='ignore'):
          x.remove(f clean_dir(root):
      '''remove .* and _* files and directories under root'''
      for x in root.walkdirs('.*', errors='ignore'):
          x.rmtree()
      for x in root.walkdirs('_*', errors='ignore'):
          x.rmtree()
  
      for x in root.walkfiles('.*', errors='ignore'):
          x.remove()
      for x in root.walkfiles('_*', errors='ignore'):
          x.remove()
docs: remove .* and _* files and directories under root