title: How to view code of predefined library functions in Python libraries?
body: <p>I use Quantlib and other packages for building a library of valuation models for derivative financial instruments in Python.</p>
  
  <p>Some of the pre-defined functions I use a lot. I would like to understand the code underlying the functions in the libraries I use. Is there a way for me to do that? I am especially interested in the functions offered by Numpy and, Quantlib.</p>