How can i design a band-pass filter with scipy?

[LabWINC]

Hi all,
i would like to design a high pass filter with scipy.signal module.

This is the code i'm using to:

import scipy.signal as signal
import scipy

#first of all i design the lowpass fir filter. This is a 10 taps filter
with cutoff frequency =1 (as help tell me to do)

lpwindow=signal.firwin(10,1)

#with the following instruction i'm creating a band pass filter from
the low pass one
bpwindow=signal.lp2bp(lpwindow,1,0.5,0.2)

My problem is that the band-pass filter obtained with lp2bp function is
16 taps one!
How is it possible??

thanks,

Vincenzo