test.py

import os

homedir    = os.getcwd()
part_name  = '201211981222_7a214d288112fe8ef99944aa7ce4d228'
path       = '/static/upload/post_img/2012/11/9'
imgPath    = homedir + path

if os.path.isfile(imgPath + '/.DS_Store'): 
    os.remove(imgPath + '/.DS_Store')

files      = os.listdir(imgPath)

for file in files:
    p = file.split('.')[0]
    p2 = p.split('_',2)[0]
    p3 = p.split('_',2)[1]

    if p2+'_'+p3 == part_name:
        file = imgPath + "/" + file
        os.remove(file)