title: Big-O of loop over dictionary
body: <p>I'm interested in the big-O complexity of a loop over the same dictionary twice and then loop over the length of a specific key in the dictionary, as shown in the pseudocode. What is the Big-O for each loop, and what would the final Big-O be?</p>
  
  <p>I have tried looking at other big-O threads in here, but they are either confusing to me, due to my restricted knowledge of big-O, or not as case specific as what I'm looking for.</p>
  
  <p>Thanks</p>
  
  <pre><code>dictionary = A dictionary with 100 keys and corresponding values of 10-20 characters each
  
  for Akey in dictionary:
      do something
      for Bkey in dictionary:
          do something
          for i in range(len(dictionary[Bkey]))
              do something
  </code></pre>