how to find the facet-sphere contact

I want to get the contact information about the shaft and spheres.

below is the code:
########################################
O.reset()
facets = O.bodies.append(geom.facetCylinder((0.2,0.2,0.3),0.2,0.6,wallMask=6,segmentsNumber=6))
print('the ids of the facets:',facets)

x0=0.2;y0=0.2;z0=0.2
cylinderIDS= O.bodies.append(geom.facetCylinder((x0,y0,z0),
 radius=0.08,height=0.3,orientation=Quaternion((1, 0, 0), 0),wallMask=7,segmentsNumber=6, angleRange=None))

print('here is the ids for the cylinder:',cylinderIDS)

facets2 = O.bodies.append(geom.facetCylinder((0.2,0.2,0.9),0.2,0.6,wallMask=4,segmentsNumber=6))

from yade import pack, plot,export
sp=pack.SpherePack()
sp.makeCloud((0.07,0.07,0.6),(0.33,0.33,1.2),rMean=.01)
sp.toSimulation()
print "num_spheres= ", len(O.bodies)

O.engines=[
 ForceResetter(),
 InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
 InteractionLoop(
  # handle sphere+sphere and facet+sphere collisions
  [Ig2_Sphere_Sphere_ScGeom(),Ig2_Facet_Sphere_ScGeom()],
  [Ip2_FrictMat_FrictMat_FrictPhys()],
  [Law2_ScGeom_FrictPhys_CundallStrack()]
 ),
 NewtonIntegrator(gravity=(0,0,-98.1),damping=0.4),
 # call the checkUnbalanced function (defined below) every 2 seconds
 PyRunner(command='checkUnbalanced()',realPeriod=2),
 # call the addPlotData function every 200 steps
 #PyRunner(command='addPlotData()',iterPeriod=100)
]
O.dt=.5*PWaveTimeStep()

O.trackEnergy=True

def checkUnbalanced():
 if unbalancedForce()<.001:
  O.pause()
O.run(10000000,True)
######################### get the shaft_spheres contact ################
for i in O.interactions:
 if not i.isReal: continue
 if isinstance(O.bodies[i.id1].shape,Facet) and isinstance(O.bodies[i.id2].shape,Sphere):
  #for i.id1 in cylinderIDS:
  O.bodies[i.id2].shape.color = (0,0,0)

####################
I want to get the contact information for the inner cylinder (here I call it cylinderIDS).
when the particle falls down , I want to capture the contact force and the contact normal.

 #########: if isinstance(O.bodies[i.id1].shape,Facet) and isinstance(O.bodies[i.id2].shape,Sphere): ###### this line we can get the facet----sphere contact information. but how can I get the specific facet----sphere contact infor.
#### we know the facet IDS contains in "cylinderIDS"..
###### this line here::: for i.id1 in cylinderIDS:-----------I want to put some conditions here to confine this is the inner cylingder, but I don't know how to do it.

################################
besides, I have some another question about the i.id1 and i.id2.
If the contact is between the facet and sphere, I want to know which ids belong to facet group? which ids belong to sphere group? because here is a sentence methioned that "facet are only stored in id1 "

references:
[1]https://github.com/yade/trunk/blob/master/examples/jointedCohesiveFrictionalPM/identifBis.py

thanks!
Yong