title: how to use re.findall to find the words that is NOT of all uppercase letters?
body: <p>For example I have <code>s="I REALLY don't want to talk about it, not at all!"</code></p>
  
  <p>I want <code>re.findall(reg, s)</code> to return 
  <code>"I"  "don't"  "want" "to" "talk" "about" "it" "," "not" "at" "all" "!"</code></p>
  
  <p>So far I got <code>reg=r'[^\w\s]+|\w+|\n'</code>   which can not filter out the word <code>"REALLY"</code></p>
  
  <p>thanks</p>