title: Syntax error in Colab, using the exclamatory mark (!)
body: <p>To remove all the files except for two:</p>
  
  <p><code>!rm -rf !("file1"|"file2")</code> </p>
  
  <p>But this gave error:</p>
  
  <p><code>/bin/bash: -c: line 0: syntax error near unexpected token</code>('`</p>
  
  <p>What syntax should be used as an alternative?</p>