title: Chained Conditions that require order to not produce order
body: <p>Whenever I <strong>chain conditions</strong> in Python (or any other language tbh) I stumble upon asking myself this, kicking me out of the productive "Zone". 
  When I chain conditions I can, by ordering them correctly, check conditions that without checking for the other conditions first, may produce an Error.</p>
  
  <p>As an example lets assume the following snippet:</p>
  
  <pre class="lang-py prettyprint-override"><code>if "attr" in some_dictionary and some_value in some_dictionary["attr"]:
      print("whooohooo")
  </code></pre>
  
  <p>If the first condition wasnt in the first place or even absent, the second condition my produce an <code>KeyError</code></p>
  
  <p>I do this pretty often to simply save space in the code, but I always wondered, if this is good style, if it comes with a risk or if its simply "pythonic".</p>