title: Converting a list of list to a string with a delimiter of choice in the place of comma
body: <p>Here is a sample list of lists:</p>
  
  <pre><code>sample = [[6594, 3084, 6956, 3429], [6401, 1154, 6693, 1436], [6463, 712, 6754, 1015]]
  </code></pre>
  
  <p>Now I have a requirement that there are to be no commas in the string, so inside a sub-list, I have to replace the comma with ":" and the comma between the two lists will have to be replaced with "|". </p>
  
  <p>Finally, the output will look like this:</p>
  
  <pre><code>"6594: 3084: 6956: 3429|6401: 1154: 6693: 1436|6463: 712: 6754: 1015"
  </code></pre>
  
  <p>I tried using the join method by first converting the list of lists to string:</p>
  
  <pre><code>sample = str([[6594, 3084, 6956, 3429], [6401, 1154, 6693, 1436], [6463, 712, 6754, 1015]])
  final_result = "|".join(sample)
  </code></pre>
  
  <p>This yielded me the output string:</p>
  
  <pre><code>'[6594, 3084, 6956, 3429]|[6401, 1154, 6693, 1436]|[6463, 712, 6754, 1015]'
  </code></pre>
  
  <p>So this is half-way through.
  But then I cannot again apply the join method as each number is a string and I will get a funny-looking output. </p>
  
  <p>I understand that writing a nested for loop will solve this issue, but is there a more elegant approach like using "join" or "map" or any such similar methods?</p>
  
  <p>Note: The output has to be in the string format as shown above.</p>