title: how to get python to print different responses to similar input
body: <p>I need python to go through a list of names and print the following:
  first time it sees a name it prints "welcome name" (got that)
  second time it sees a name it prints "welcome back name".
  What I have so far is that if the name appears more than once, it will be appended to a second list. How can I get python to print welcome the first time it sees the name and welcome back the second?</p>
  
  <pre><code>guests=input("What are the names of the guests? ")
  guests=guests.split(",")
  m=()
  for i in guests:
    if guests.count(i)&gt;1:
     m.append(i)
          for i in m:
     else:
      print ("Welcome, ", i)
  </code></pre>