title: How can I make an rx.py Observable from a stream such as stdin?
body: <p>I'm trying to get my head around the <code>rxpy</code> library for functional reactive programming (FRP) and I've already hit a roadblock.  I'm writing a small program that expects data to be streamed in via standard input (<code>sys.stdin</code>).</p>
  
  <p>My question is therefore simple:  how can I create an <code>rx.Observable</code> instance that will asynchronously read from stdin?  Are there built-in mechanisms to create <code>Observable</code> instances from streams?</p>