title: strip() works selectively on the input function but properly on a string literal
body: <p>I am trying to understand the <code>strip()</code> function. And I'm seeing a confusing behavior.</p>
  
  <pre><code>import sys
  test = input().strip('e')
  print(test)
  
  N = input().strip('cmowz.')
  print(N)
  
  print('www.example.com'.strip('cmowz.'))
  </code></pre>
  
  <p>This gives the following output:</p>
  
  <pre><code>test   message  here   
  'www.example.com'
  example
  </code></pre>
  
  <p>So what I'm seeing is that calling <code>input().strip()</code> method works properly for trailing and leading spaces. But it doesn't work for anything else.</p>
  
  <p><code>input().strip('e')</code> doesn't really strip e from the string.</p>
  
  <p>However, calling a string literal <code>"somethinghere".strip('e')</code> works fine.</p>
  
  <p>Can someone please explain this inconsistent behavior?</p>