title: numpy's complex128 conversion
body: <p>I have a list of np.complex128 numbers but for all the numbers the complex part is equal to zero. How can I extract the real part of the number (which is pretty much the only part of the number)?</p>
  
  <p>As a side not, I want to do scipy integration but I am not sure whether their integration methods can handle y samples with dtype of np.complex128. </p>