Max Influence Selector - Maya Python by Mauricio Pachon

import maya.cmds as cmds

'''Runs through a skin cluster and the selected vertices to find if any
of them have more than a certain amount of joints influencing them, then
lists them and selects them'''

#Skin cluster you want to check#
sCluster = 'YourSkinClusterHere'
#List anything that has above this value of influence#
ammount = 0.001
#List anything that has more than X ammount of influences#
number = 4

aboveInfluence= []
for s in cmds.ls(sl = True, fl = True):
    #Runs through the selected vertices checking for the specified ammount#
    influence = cmds.skinPercent(sCluster, s, ib = ammount, q = True, t = None)
    if len(influence) > number:
        #Puts all that have above X number of joints as influences in a list#
        aboveInfluence.append(s)
        print 'Vertex: ' + s + ' ' + 'No. of Influences: ' + str(len(influence)) + ' ' + 'Influences: ' + str(influence)

#Selects all vertices that have met the specified parameters#
cmds.select(aboveInfluence)
print aboveInfluence