title: Convert (screenshot captured) image to base 64 without saving to png/jpeg in python
body: <p>I saw a lot of q&amp;a about converting images to base 64 string from image, all of them involving saving the image physically on pc.
  What I want is convert the image to base 64 string without the need to save the image physically.</p>
  
  <p>How can I do it with <code>pyscreenshot</code> or <code>ImageGrab</code>?</p>