from pymol import cmd,stored
def average_b(selection):
stored.tempfactor = 0
stored.atomnumber = 0
cmd.iterate(selection, "stored.tempfactor = stored.tempfactor + b")
cmd.iterate(selection, "stored.atomnumber = stored.atomnumber + 1")
print("Your selection: %s" % selection)
print("sum of B factors: %s" % stored.tempfactor)
print("number of atoms: %s" % stored.atomnumber)
averagetempfactor = stored.tempfactor / stored.atomnumber
print("average B of '%s': %s" % (selection, averagetempfactor))
cmd.extend("average_b", average_b)
