Jira python calculate time

I am trying to calculate the time from the issue is created and until it is resolved. With these fields:

creation_time = issue.fields.created
resolved_time = issue.fields.resolutiondate

Output when I print:

Creation: 2016-06-09T14:37:05.000+0200 Resolved: 2016-06-10T10:53:12.000+0200

Is there anyway I can minus the resolution date and time with the creation date and time to find how much time is spent on a issue?