title: Add a '.' for every string in a list of lists, if string[-1] != '.'
body: <p>I have a list of lists like this:</p>
  <pre><code>text_lst = [['this is a string.','this is a string2'],['this is not a string'],['this is a string with numbers!','that is all!']]
  </code></pre>
  <p>I need to add a <code>.</code> for every string that does not end with a <code>.</code>. Below is my code:</p>
  <pre><code>new_lst = []
  for x in text_lst:
      for x1 in x:
          if x1[-1] != '.':
              new_lst.append(x1 + '.')
          else:
              new_lst.append(x1)
  </code></pre>
  <p>However, it returns a weird combination of strings and list:</p>
  <pre><code>[['this is a string.', 'this is a string2'],
   'this is a string2.',
   'this is not a string.',
   'this is a string with numbers!.',
   'that is all!.']
  </code></pre>
  <p>I'm expecting this type of result:</p>
  <pre><code>[['this is a string.', 'this is a string2.'],
   ['this is not a string.'],
   ['this is a string with numbers!', 'that is all!']]
  </code></pre>
  <p>Can you kindly let me know what did I do wrong?</p>
  <p>Edit:
  I used the wrong variable, instead of appending <code>x1</code>, I append <code>x</code>. Here's the result:</p>
  <pre><code>['this is a string.',
   'this is a string2.',
   'this is not a string.',
   'this is a string with numbers!.',
   'that is all!.']
  </code></pre>
  <p>However, any suggestion on how to preserve the list of lists format like the original one?</p>