code: def imshow(arr):
      """
      Simple showing of an image through an external viewer.
  
      This function is only available if Python Imaging Library (PIL) is installed.
  
      Uses the image viewer specified by the environment variable
      SCIPY_PIL_IMAGE_VIEWER, or if that is not defined then `see`,
      to view a temporary file generated from array data.
  
      .. warning::
  
          This function uses `bytescale` under the hood to rescale images to use
          the full (0, 255) range if ``mode`` is one of ``None, 'L', 'P', 'l'``.
          It will also cast data for 2-D images to ``uint32`` for ``mode=None``
          (which is the default).
  
      Parameters
      ----------
      arr : ndarray
          Array of image data to show.
  
      Returns
      -------
      None
  
      Examples
      --------
      >>> a = np.tile(np.arange(255), (255,1))
      >>> from scipy import misc
      >>> misc.imshow(a)
  
      """
      im = toimage(arr)
      fnum, fname = tempfile.mkstemp(".png")
      try:
          im.save(fname)
      except Exception:
          raise RuntimeError("Error saving temporary image data.")
  
      import os
  
      os.close(fnum)
  
      cmd = os.environ.get("SCIPY_PIL_IMAGE_VIEWER", "see")
      status = os.system("%s %s" % (cmd, fname))
  
      os.unlink(fname)
      if status != 0:
          raise RuntimeError("Could not execute image viewer.")
  
file_path: catboost/contrib/python/scipy/py2/scipy/misc/pilutil.py
imports: from __future__ import division, print_function, absolute_import
  import numpy
  import tempfile
  from numpy import amin, amax, ravel, asarray, arange, ones, newaxis, transpose, iscomplexobj, uint8, issubdtype, array
label_desc: Use image node_id 7 for calling a global function with example usage: imshow(arr) without return types