title: Having issues with print statement formatting
body: <p>I have this code which works properly but I cannot figure out how to get it to format correctly.</p>
  
  <pre><code>from Stack import*
  
  def main():
  
  file=input("Enter the name of the file containing postfix expressions: ")
  file=open(file, 'r')
  
  stack=Stack()
  
  operators=["/", "*", "-", "+"]
  
  for line in file:
  
      try:
  
          print("Expression: " ,line)
          expression=line.split()
          for i in expression:
              if i not in operators:
                  stack.push(i)
  
              if i == "/":
                  x=int(stack.pop())
                  y=int(stack.pop())
                  stack.push(y/x)
  
              if i == "*":
                  x=int(stack.pop())
                  y=int(stack.pop())
                  stack.push(x*y)
  
              if i == "+":
                  x=int(stack.pop())
                  y=int(stack.pop())
                  stack.push(x+y)
  
              if i == "-":
                  x=int(stack.pop())
                  y=int(stack.pop())
                  stack.push(y-x)
  
          if stack.size() &gt; 1:
              print("Error: ",line,"is an invalid postfix expression")
          else:
              print("Answer: " ,stack.pop())
  
  
      except IndexError:
          print("Error: ",line,"is an invalid postfix expression.")
      except ValueError:
          print("Error: ",line,"is an invalid postfix expression.")
  main()
  </code></pre>
  
  <p>But the out put comes out all gross looking like this:
  I don't think it is extremely important that it looks nice but I would like for it to.</p>
  
  <pre><code>Enter the name of the file containing postfix expressions: expressions.txt
  Expression:  5 4 3 + 2 * -
  
  Answer:  -9
  Expression:  8 5 *
  
  Answer:  40
  Expression:  20 5 /
  
  Answer:  4.0
  Expression:  3 8 6 + *
  
  Answer:  42
  Expression:  3 4 + 9 - 12 +
  
  Answer:  10
  Expression:  9 3 2 1 + + /
  
  Answer:  1.5
  Expression:  3 + 4
  
  Error:  3 + 4
   is an invalid postfix expression.
  Expression:  * 3 4 5 + *
  
  Error:  * 3 4 5 + *
   is an invalid postfix expression.
  Expression:  4 9 1 3 + -
  
  Error:  4 9 1 3 + -
   is an invalid postfix expression
  Expression:  h 3 +
  
  Error:  h 3 +
   is an invalid postfix expression.
  </code></pre>
  
  <p>What is going on here?</p>