title: Vigenere Cipher for sentence with whitespaces
body: <p>I want to make a vigenere cipher program for sentences.
  For example the message is &quot;Introducing my best friend carly&quot; and the keyword is &quot;climb&quot;</p>
  <pre><code>y = &quot;Introducing my best friend carly&quot;
  target_length = len(y)
  
  def repeat_string(a_string, target_length):
      number_of_repeats = target_length // len(a_string) + 1
      a_string_repeated = a_string * number_of_repeats
      a_string_repeated_to_target = a_string_repeated[:target_length]
      return a_string_repeated_to_target
  
  a_string = &quot;climb&quot;
  
  print (y)
  print(repeat_string(a_string, target_length))
  </code></pre>
  <p>The output is</p>
  <pre><code>Introducing my friend carly
  climbclimbclimbclimbclimbcl
  </code></pre>
  <p>While the output that i wanted is</p>
  <pre><code>Introducing my friend carly
  climbclimbc li mbclim bclim
  </code></pre>
  <p>How to do that?</p>