title: About the order Set List
body: <p>I have a problem, I want to list the different words in 2 words with set_list. This is my code;</p>
  
  <pre><code>def set_word(str1,str2):
      set_list=set()
      for i in str1:
          if i not in str2:
              set_list.add(i)
      for i in str2:
          if i not in str1:
              set_list.add(i)
      return set_list
  
  str1=str(input("word1:"))
  str2=str(input("word2:"))
  x=set_word(str1,str2)
  result=""
  for i in x:
      result+=i
  print("Different word:",result)
  </code></pre>
  
  <p>Actually, my code works the way I want it. But every time the 'result' sequence is different. </p>
  
  <p>e.g:
  first try:</p>
  
  <pre><code>      result="abc"
  </code></pre>
  
  <p>e.g:
  second try:</p>
  
  <pre><code>      result="bca"
  </code></pre>
  
  <p>What is the reason of this?</p>
  
  <p>Thanks everyone!</p>