title: Two different definition of strip method in Python (2.7.14rc1) official documentation? str.strip([chars]) vs string.strip(s[, chars])
body: <p>When I search the strip method for a string in Python (2.7.14rc1) official documentation, I found out there are two definitions. That is <code>str.strip([chars])</code> and <code>string.strip(s[, chars])</code></p>
  
  <p>My question is: What are the differences between the two definitions? Which one should I follow?</p>
  
  <p><code>str.strip([chars])</code> is in 5. Built-in Types section: <a href="https://docs.python.org/2/library/stdtypes.html#str.strip" rel="nofollow noreferrer">https://docs.python.org/2/library/stdtypes.html#str.strip</a></p>
  
  <p><code>string.strip(s[, chars])</code> is in 7. String Services section:<a href="https://docs.python.org/2/library/string.html#string.strip" rel="nofollow noreferrer">https://docs.python.org/2/library/string.html#string.strip</a></p>