title: Extract all numbers in brackets with Python
body: <p>i have a string looking like this:</p>
  
  <pre><code>s = "asd[123]348dsdk[45]sdhj71[6789]sdfh"
  </code></pre>
  
  <p>i need an other string that contains the numbers in brackets like this:</p>
  
  <pre><code>s_filter = "123 45 6789"
  </code></pre>
  
  <p>Sorry for not posting my own ideas!
  i tried to use this:</p>
  
  <pre><code>s = "asd[123]348dsdk[45]sdhj71[6789]sdfh"
  s_filter = s[s.find("[")+1:s.find("]")]
  
  result: s_filter = "123"
  </code></pre>
  
  <p>But it only gives me the first numbers.</p>
  
  <p>Any ideas?</p>
  
  <p>Best,
  Hans</p>