python + maya: shading

can also use the following commands:
cmds.sets( name='redMaterialGroup', renderable=True, empty=True )
cmds.shadingNode( 'phong', name='redShader', asShader=True )
cmds.setAttr( 'redShader.color', 1, 0, 0, type='double3' )
cmds.surfaceShaderList( 'redShader', add='redMaterialGroup' )
cmds.sets( 'plane1', e=True, forceElement='redMaterialGroup' )

i=0
n = 50
limit = 20
lamb = []
lambSG = []
while i< n:
    size = random.uniform(0.1, 5)
    names = polyCube(o=True, w=size, h=size, d=size)
    k=0
    for name in names:
        print(str(k) + ": " + name)
        k = k + 1
    cube = names[0] # object name
    node = names[1] # node name

    lamb=lamb + [createNode('lambert', n=('lamb' + str(i)))]; # create lambert shader node
    lambSG= lambSG + [sets(n='lambSG'+str(i), empty=True, r=True, nss=True )] # create an empty shading group
    connectAttr( lamb[i]+".outColor", lambSG[i]+".surfaceShader", force=True) # connect attribute

    r = random.uniform(0, 1)
    g = random.uniform(0, 1)
    b = random.uniform(0, 1)

    setAttr(lamb[i]+".color", r, g, b, type='double3' ); # set to random colour
    sets(cube, fe=lambSG[i]) # set cube to have the above shading group

    move(random.uniform(-limit, limit),
         random.uniform(-limit, limit),
         random.uniform(-limit, limit), cube, r=True) 
    i = i+1