用Python改变文件的MD5码

import os, glob

def fileAppend(filename):
myfile = open(filename,'a')
myfile.write("####&&&&%%%%")
myfile.close

if __name__ == '__main__':
dirname = r'C:\Users\XXXX\Desktop\New folder'
allFile = glob.glob(dirname + os.sep + '*.mp4')

for filename in allFile:
fileAppend(filename)
print(filename + 'is Changed.')