title: How can I more easily suppress previous exceptions when I raise my own exception in response?
body: <p>Consider</p>
  
  <pre><code>try:
     import someProprietaryModule
  except ImportError:
     raise ImportError('It appears that &lt;someProprietaryModule&gt; is not installed...')
  </code></pre>
  
  <p>When run, if someProprietaryModule is not installed, one sees:</p>
  
  <pre><code>(traceback data)
  ImportError: unknown module: someProprietaryModule
  
  During handling of the above exception, another exception occurred:
  
  (traceback data)
  ImportError: It appears that &lt;someProprietaryModule&gt; is not installed...
  </code></pre>
  
  <p>Perhaps I don't want the "During handling of the above exception..." line (and the lines above it) to appear. I could do this:</p>
  
  <pre><code>_moduleInstalled = True
  try:
     import someProprietaryModule
  except ImportError:
     _moduleInstalled = False
  if not _moduleInstalled: 
     raise ImportError('It appears that &lt;someProprietaryModule&gt; is not installed...')
  </code></pre>
  
  <p>But that feels like a bit of a hack. What else might I do?</p>