using tapers function with "percentage" option

Hi all,

I want to substitute the command of sac( http://www.iris.edu/files/sac-manual/commands/taper.html ):
* TAPER TYPE HANNING WIDTH 0.05

with the equivalent one in obspy. I'm trying to use taper ( http://docs.obspy.org/packages/autogen/obspy.core.trace.Trace.taper.html?highlight=taper#obspy.core.trace.Trace.taper ) where type is hann and is specified by this function ( http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.hann.html#scipy.signal.hann ).
I don't understand how to do it.

Any suggestions?

Thank you, in advance