title: Get the offset for a specific time and timezone in python
body: <p>I need a function that will return the offset for a specific timezone at a specific moment. I have the timezone in a string variable in the format <code>America/Los_Angeles</code> and I have the date in format <code>2014-12-01</code></p>
  
  <p>The offset needs to be DST sensitive, meaning that for Los Angeles, it should return -07 during summer and -08 during winter.</p>