title: python how to extract operators from string
body: <p>I want to extract operators like: <code>+,-,/,*</code> and also <code>(,),_</code> from the string</p>
  
  <p>Eg.</p>
  
  <pre><code>a-2=b
  (c-d)=3
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>- ,=, (, -, ), = 
  </code></pre>
  
  <p>This does not work: </p>
  
  <pre><code>re.finditer(r'[=+/-()]*', text)
  </code></pre>