title: Python Challenge level 3 - Solving with string slicing
body: <p>apologies to posting the question, as has been answered in other questions as well. However, couldn't figure out what's wrong with this solution. The question requires to find the lower-cased characters bordered by 3 upper-cased characters on each side.  The code i've writting:</p>
  
  <pre><code>q = ''
  for i in range(4,len(x)-4):
      if x[i].islower() and x[i-4].islower() and x[i+4].islower() and x[i-3:i].isupper() and x[i+1:i+4].isupper()  :
          q+=x[i]
  
  
  print(q)
  </code></pre>
  
  <p>The string i'm getting is </p>
  
  <blockquote>
    <p>'lgvcaaginbkvsoezhtlnldslyitlooqfgiksudtm' 
    vs 'linkedlist'</p>
  </blockquote>
  
  <p>Thanks for the help. </p>
  
  <p>Edit: for some reason the following code seems to work:</p>
  
  <pre><code>q = ''
  for i in range(4,len(x)-4):
      if x[i].islower() and x[i-4].islower() and  x[i-3:i].isupper() and x[i+1:i+4].isupper() and x[i+4].islower():
          q+=x[i]
  
  print(q)
  </code></pre>