title: How to replace all T with U in an input string of DNA?
body: <p>So, the task is quite simple. I just need to replace all &quot;T&quot;s with &quot;U&quot;s in an input string of DNA. I have written the following code:</p>
  <pre><code>def transcribe_dna_to_rna(s):
  base_change = {&quot;t&quot;:&quot;U&quot;, &quot;T&quot;:&quot;U&quot;}
  replace = &quot;&quot;.join([base_change(n,n) for n in s])
  return replace.upper()
  </code></pre>
  <p>and for some reason, I get the following error code:</p>
  <pre><code>'dict' object is not callable
  </code></pre>
  <p>Why is it that my dictionary is not callable? What should I change in my code?
  Thanks for any tips in advance!</p>