title: Is this the same code for python dictionary?
body: <p>If D is a python dictionary, are these two lines the same thing?</p>
  
  <pre><code>if d in D:
  </code></pre>
  
  <p>VS:</p>
  
  <pre><code>if d in D.keys():
  </code></pre>
  
  <p>I am reading other people' code and found these two lines in very close locations. I think they should be the the same and should be changed to the first version. Right?</p>