folder_files_rename.py

import glob
import os, time

time_and_file=dict()
folder_name=raw_input()
ct=1
#assuming folder at the same directory as script
for filename in glob.glob(folder_name+"/*.*"):
	name=filename.split('.')[0]
	try:
		extension=filename.split('.')[1]
	except:
		#sometimes text file may not have extensions
		extension=""
	if len(extension):
		newname=name+"_"+str(ct)+"."+extension
	else:
		newname=name+"_"+str(ct)
	os.rename(filename, newname)
	ct+=1	
	access_time=str(time.ctime(os.stat(newname).st_atime))
	
	try:
		#some files might have been accesse simultaneously thus keeping them in list
		time_and_file[access_time].append(newname)
	except:
		time_and_file[access_time]=[newname]

last_access_list=[]
for t in sorted(time_and_file.keys()):
	for name in time_and_file[t]:
		last_access_list.append(name.replace(folder_name+'/',''))
print last_access_list