title: While Loop stop with blank input
body: <p>How can I make the while loop stop when the x input is blank instead of it stopping when the word 'stop' appears?</p>
  <p>This is what I did but with 'stop'. However if  I change the condition to x!=' ', when I try to convert x into an int it breaks.</p>
  <pre><code>x=''
  y=''
  list=[]
  while x!='stop':
      x=input('x input: ')
      y=int(input('y input: '))
      if x!='stop':
          list.append((int(x),y))
      
  print('Stop')
  print(list)
  </code></pre>