An IDA python script that hides long sequences of nops to make the tree more readable.

nop-hidder

from idautils import *
from idc import *

mnemonics = dict()
hides = []
in_nop_sled = 0 
curr_pos = 0 
sled_len = 0 

for seg_ea in Segments():
    for head in Heads(seg_ea, SegEnd(seg_ea)):
        if isCode(GetFlags(head)):        
            mnem = GetMnem(head)
            if mnem == 'nop':
                sled_len += 1
                if in_nop_sled == 0:
                    curr_pos = head
                    in_nop_sled = 1
            else :
                if in_nop_sled == 1 :
                    in_nop_sled = 0
                    hides.append([curr_pos,sled_len])
                    curr_pos = 0 
                    sled_len = 0 

for h in hides:
	if h[1] > 1:
		HideArea(h[0],h[0]+h[1],'','','',0)

print 'Done hidding...'

api and docs for ida functions

http://read.pudn.com/downloads151/doc/656614/idapython-1.0.0/python/idautils.py__.htm
https://www.hex-rays.com/products/ida/support/idadoc/162.shtml