title: object has no attribute 'append' in python while using a imported file
body: <p>I keep getting an attribute error with this code.  Does anyone have any ideas why this might be the case?  I know 'str' cannot be appended but I am trying to append the list... any help would be greatly appreciated!</p>
  
  <pre><code>elif choice == "1":
      i=0
      eval_type = open("eval_type.txt", "r+")
      for line in eval_type:
          i+=1
          new_eval = input("What do you want to call the new evaluation?")
          points = input("How many points is this type worth?")
          if new_eval in line:
              print("\n", new_eval, "already exists.")
          else:
              eval_type.append(new_eval)
              print (new_eval, "has been added.")
      eval_type.close()
  </code></pre>