title: How to view the implementation of python's built-in functions in pycharm?
body: <p>When I try to view the built-in function all() in PyCharm, I could just see "pass" in the function body. How to view the actual implementation so that I could know what exactly the built-in function is doing?</p>
  
  <pre><code>def all(*args, **kwargs): # real signature unknown
      """
      Return True if bool(x) is True for all values x in the iterable.
  
      If the iterable is empty, return True.
      """
      pass
  </code></pre>