title: Behaviour of .reverse() function in python
body: <p>I'm coming from an R background and am confused about the following:</p>
  
  <p>Suppose I had "hello" in list format saved in the variable <em>txt</em>. Thus</p>
  
  <pre><code> txt=  ['h','e','l','l','o']
  </code></pre>
  
  <p>After some testing, the following works:</p>
  
  <pre><code>txt.reverse()
  "."join(txt)
  </code></pre>
  
  <p>and produces as expected <em>olleh</em>.</p>
  
  <p>However, the following does <strong>not</strong> work:</p>
  
  <pre><code>"".join(txt.reverse())
  </code></pre>
  
  <p>It gives an error. I'm curious why that is the case as I thought I can "nest" function calls within function calls?</p>
  
  <p>Thank you for helping!</p>