def get_blocks_diff(a,b):
d=difflib.Differ()
res_r=[]
cb_r=[]
res_l=[]
cb_l=[]
change_l=False
change_r=False
result=list(d.compare(a.splitlines(), b.splitlines()))
#from pprint import pprint
#pprint(result)
for i in result:
data=i[2:]
if i[:2]=='? ':
continue
if i[:2]==' ':
if not change_l and not change_r:
cb_r.append(data)
cb_l.append(data)
elif not change_l and change_r:
res_r.append(cb_r)
cb_r=UserList([data])
cb_l.append(data)
elif change_l and not change_r:
res_l.append(cb_l)
cb_l=UserList([data])
cb_r.append(data)
elif change_l and change_r:
res_r.append(cb_r)
cb_r=UserList([data])
res_l.append(cb_l)
cb_l=UserList([data])
change_r=False
change_l=False
elif i[:2]=='- ':
if not change_l:
res_l.append(cb_l)
cb_l=UserList([data])
elif change_l:
cb_l.append(data)
cb_l.added=True
change_l=True
#print "1"
elif i[:2]=='+ ':
if not change_r:
res_r.append(cb_r)
cb_r=UserList([data])
elif change_r:
cb_r.append(data)
cb_r.added=True
change_r=True
if len(cb_r)>0: res_r.append(cb_r)
if len(cb_l)>0: res_l.append(cb_l)
return res_l, res_r
