PyMel makes your code pretty and slow.

pymel_sucks.py

import timeit

pymel_setup = '''
import pymel.core as pm
def create_sphere():
    s = pm.polySphere()[0]
    for vertex in s.vtx:
        vertex.setPosition((10, 10, 10))
    pm.delete(s)'''

cmds_setup = '''
import maya.cmds as cmds
def create_sphere():
    s = cmds.polySphere()[0]
    for vert_index in range(cmds.polyEvaluate(s, vertex=True)):
        cmds.xform('{0}.vtx[{1}]'.format(s, vert_index), translation=(10,10,10))
    cmds.delete(s)'''

print('PyMel', timeit.timeit('create_sphere()', setup=pymel_setup, number=10))
print('Maya Cmds', timeit.timeit('create_sphere()', setup=cmds_setup, number=10))