title: Python: SpooledTemporaryFile suffix not working
body: <p>I want to write an image using opencv to a temporary file, get the path of that temporary file and pass that path to a function.</p>
  
  <pre><code>import cv2 as cv
  from tempfile import NamedTemporaryFile, SpooledTemporaryFile
  
  img = create_my_awesome_image()
  
  with NamedTemporaryFile(suffix=".png") as temp:
      print(temp.name)
      cv.imwrite(temp.name, img) # this one sparks joy
  
  with SpooledTemporaryFile(max_size=1000000, suffix=".png") as temp:
      print(temp.name)
      cv.imwrite(temp.name, img) # this one does not
  
  </code></pre>
  
  <p>The first print prints <code>C:\Users\FLORIA~1\AppData\Local\Temp\tmpl2i6nc47.png</code>.<br>
  While the second print prints: <code>None</code>.</p>
  
  <p>Using <code>NamedTemporaryFile</code> works perfectly find. However, because the second print prints None, I cannot use the <code>SpooledTemporaryFile</code> together with opencv. Any ideas why the prefix argument of <code>SpooledTemporaryFile</code> is ignored?</p>