Use basestring in dataset
Use basestring in dataset

cpaulik/xray,kjordahl/xray,markelg/xray,jhamman/xarray,pydata/xarray,xray/xray,clarkfitzg/xray,markelg/xray,jhamman/xarray,jhamman/xray,pydata/xarray,shoyer/xray,hetland/xray,kjordahl/xray,shoyer/xarray,pydata/xarray,rabernat/xray,petercable/xray,cpaulik/xray,jhamman/xarray,markelg/xray,hetland/xray,shoyer/xarray,chunweiyuan/xarray,drewokane/xray,jcmgray/xarray,clarkfitzg/xray,NicWayand/xray,rabernat/xray